Research Paper to Read: (2004) Effect of feeding frequency on growth and fecundity in an ornamental fish, Betta splendens (Regan)

Source: ResearchGate.

(1) Two meals per day is the optimum frequency for growth, gonad (a testis or ovary) development, and fecundity (fertility on producing eggs).
(2) Don't overfed (three times per day) your female Bettas as it will increase it's mortality rate and reduce eggs production.
(3) 14 days is sufficient enough for subsequent spawn for a female Betta.

Why this paper?
One of the question when rearing and breeding Betta splendens is how frequent we should feed the fish to achieve optimum growth and speed up breeding. There are many inconsistent advice given by different breeders on the number of times the fish should be fed. Nevertheless, going through scientific literature will give us a baseline to feed our fishes at the optimum level without unnecessary food waste. However, this does not discounts the vast years of experience of master breeders as typical scientific research was done once compare to years of multiple trials and errors of some breeders.

Material and Methods
This experiment includes 375 juveniles Betta of 30 days old with weight of 0.045±0.01 g and lenght of 14.43±2.2 mm (not sure full length of just body only). The fishes were grouped into 15 groups of 25 each with three sets of each feeding frequency as shown below:

(1) One meal in three days (at 6:00).
(2) One meal in two days (at 6:00).
(3) One meal in one day (at 6:00).
(4) Two meals a day (6:00, 18:00).
(5) Three meals a day (6:00, 12:00, 18:00).

Breeding conditions for 77 days, roughly 2.5 months.

(1) 110-l circular cement cistern with measurement of 53.34 x 45.72 cm (the rounded container typically used by Thai Betta farm).
(2) 50l unchlorinated well fresh water. Tank were drained bi-weekly (didn't mentioned how much water)
(3) Temperature averaged 28±1C,
(4) pH 7.8±0.05.
(5) Water hardness 316±15 mg CaCO3/l, ammonia 1.01±0.12 mg/l and DO 4.04 ppm.
(6) Fresh minced beef liver (protein 35.44%, fat 3.86%, ash, 13.91%, and nitrogen free extract 46.79%)

Calculation of each type of measurements as follows:

(1) Growth. Calculation initial dry weight using electrical monopan balance. Five fishes were sacrificed (not sure how). Weight is determined every 14 days.
(2) Gonad. Calculation initial gonad weight using electrical monopan balance and gonadosomatic index (GSI). Three female fishes sacrificed (not sure how) every 14 days.
(3) Spawning. Upon attaining sexual maturity (did not mention when), two pairs of male and females where selected to spawn in a plastic container with water depth of 15cm. Eggs (hatched or unhatched) counted using sterilized needle.

While the growth rate was expected for those with higher frequency feeding, there was no significant differences between two meals and three meals per day. Interestingly result of spawning size. As the result below shown, if the female Betta was overfeed (three meals per day), the eggs production will decrease. We're quite surprised that second and third spawn yields even more eggs after every 14 days.

It seemed what we did with our breeding project was significantly not helpful to our female Bettas. To increase eggs productions, we've fed both male and female Bettas four meals per day. The result have shown that overfed actually decreased the eggs production and can cause bloating and dropsy. We've observed some of our female Bettas experienced such symptoms after mating.

Further Questions
(1) The paper did not address the impact of different meal plans for juveniles fish from 1st till 30th day. It only accounts for fish starting for 30 days old.
(2) Why not jar each juveniles fish and measure its growth, gonad development, and fecundity individually in separate container instead of one large 110-l circular cement cistern.
(3) To prevent bloating, some breeders skip Sunday meal so that the fish can fast to clear out all its waste. Will this have any significant differences to the result for those 3 meals per day?

UMT MOOC: Ornamental Fish Culture - Topic 3: Quality Characteristic Determination - Angelfish & Schooling Fish

Continue from previous post.

Discussion on quality characteristics for Angelfish and Schooling fish.

Angelfish. If you're are a beginner aquarist, there is nothing wrong to start with Angelfish or also known as Pterophyllum. Buy juvenile fishes as it's cheaper and they grow very fast. Furthermore, Angelfish is a good addition to your community tank.

On standard, there is one, a conformation (shape or structure) standard of Angelfish by the The Angelfish Society for hobbyists and breeders. The quality characteristics includes (1) Bodies, where round and slightly higher is preferred, no bump in head, appropriate eye to body ratio (2) Un-paired fins, regardless the length, needs to be straight, (3) Colours and patterns, stripes should run through the whole height of the body, (4) Size, bigger is better, (5) Deportment (behaviour), bold, alert, and active is a sign of good health.

For a list of different strains of Angelfish, see the video below.

Schooling fish, a group of fish that stay and swim together. Typical ornamental fishes are Tetra, Barb, Rasbora, and Minnow. As these species are rather on the smaller size, for example, Tetra, there isn't much individual aesthetic characteristics besides the usual sharp colours and symmetry body shapes and fins.

UMT MOOC: Ornamental Fish Culture - Topic 3: Quality Characteristic Determination - Koi & Discus

Continue from previous post.

This post will delve into the acceptable standards for quality Koi and Discus fish. As I mentioned in my previous posts before, the beauty is in the eye of the beholder. If you're a hobbyist, the first question you should ask yourself. Do you like the fish? Are you excited? If so, regardless the standards, go for what you like. A fish personalities or deportments is hard to gauge and subjective by person to person. Nevertheless, let's continue with our discussions.

Koi fish. Due to enormous varieties and rivalry between breeders around the world, it's quite hard to finalize on which is the best koi. However, there are some guidelines on quality koi which can be summarized into four characteristics: (1) Size where shape, volumes as well as fins are symmetry,  (2) Colours should be deep, intense, and uniform, (3) Patterns should be uniform, scale should be sharp, and not dirty marks, and (4) Presence as in personality and vitality.

The video below should gives us some clues on top notch quality Koi.

Discus fish or I like to call it pancake fish. It seemed we still don't have a good published standard even though there were many competitions held? The general consensus rules for good quality Discus are: (1) Overall impression, the wow factor. (2) Size of the fish on its proportion, the body shape is round and high, (2) Fins are long and extended, symmetry, and good proportion to the body (3) Colours are vivid and unique clear pattern and (4) Eyes size and colour as well as the proportion to the body size, and (4) Swimming pattern is steady. Below is the video on how juries judge Discus fish.

Examples are the show grade Discus at 2nd European Discus Championship as shown in video below.

UMT MOOC: Ornamental Fish Culture - Topic 3: Quality Characteristic Determination - Goldfish

Continue from previous post.

As mentioned in previous post, standard for any fish species serves two main purposes. First, it's used as guidelines for any competitions. Second, it guides breeder to select the best pair of fishes with desired characteristics for breeding project. For Goldfish, there exists three competing or complementary standards (there should be more from China and Japan):

(1) American Goldfish Association (AGA) Goldfish Standards, Revised 2009.
(2) Nationwide Goldfish Societies UK, Revised 2016.
(3) Federation of British Aquatic Societies (FBAS), Eleventh Edition, 2002.

Something about breeders, competitions, and standards. Breeders are the most passionate type of people around and there are always conflicts and politics on standards. Case in point, the incident that leads to the two standards existed in UK.

To identify good quality Goldfish, first we need to understand the anatomy of this species as shown in picture below (Source: AGA Goldfish Standards, 2009). First morphology is different from species, Goldfish is definitely have more mutations than other ornamental fishes. The Goldfish varieties is determined by three characteristics of existence of dorsal fin, tail type, and special growth.

According to Nationwide Goldfish Societies UK's judging standard, points are given based on these five categories of body, colour, finnage, special characteristics, and condition and deportment. The last category (deportment) required special training from breeder, where how the fish swim and react to external stimuli. 

UMT MOOC: Ornamental Fish Culture - Topic 3: Quality Characteristic Determination

For a hobbyist and consumer, understanding this topic enables you, being an educated consumer to to get your money worth by buying good quality ornamental fishes. For a breeder, knowing what quality characteristics is essential to follow the breeding standard and select the right pair of fishes for your next generation breeding projects.

Evaluation of a good quality fish is based on three main criterias: body shape, colour pattern, and fins. Although there is saying of "Beauty is in the eye of the beholder", judging standards do exists to set the baseline of identifying and judging aesthetic characteristics of any ornamental fishes in competition. For example, characteristics of show grade Betta fish (Betta Splendens) has been standardize by governing standards of International Betta Congress (IBC).

What do we look for for good quality fish? First, analysis of the unique form and structure or morphology of fishes. These includes (1) Balancing in term of colours, fins, and scale, and (2) Ratio in terms of fins, scale, and body. Secondly, unique swimming pattern. For example, Betta fish fins flaring when defending its territory. To understand this, we need to learn and identify each part of the external anatomy of a fish shown below. (Source: Wikipedia)

These numbers in the picture above are: (1) Operculum (gill cover), (2) Lateral line, (3) Dorsal fin, (4) Adipose fin, (5) Caudal peduncle, (6) Caudal fin, (7) Anal fin, (8) Photophores, (9) Pelvic fins (paired), and (10) Pectoral fins (paired). Not all fishes share the same anatomy. Diversity in fish morphology is due to adaption of its environment or selective breeding. For example, Ranchu (a type of Goldfish) does not have dorsal fin.

How can we develop good "taste" for quality aesthetic fish? Nothing but keen observation and practice. For a start, if you're around any aquarium shops or fish market, try to name each part of the fish anatomy. See if you can name them all. Next, go to any competitions or look for any show grade fishes, compare with the judging guidelines and learn to grade each fish.

This Week I Learned 2019 - Week 02

Last week post or going back for old stuff instead.

What else I learned this week in separate posts? First, continue with ornamental fish culture through MOOC on body profiles and spawning behaviours, famous species, primitive or Jurassic fishes, and Goldfish. Second, the literature review of the paper on minimal water volume for intensively producing male Siamese fighting fish. And lastly, Module::CoreList is our Perl Module(s) of the Week (plMOTW).

How Photography Is Affecting Our Brains? Due to distance, camera angle, and distortion, taking selfie (around 1 foot) makes your nasal base seemed 30% larger compare to selfie taken at 5 feets away. How about normal photos? While photos can be a good memory preservation, taking and sharing photos for social medias will lead to "self presentational concern or anxiety". Instead of engaging current moment while photographing, you're being distracted. If you still need to share and want to fully enjoy the moment, delay sharing instantly just like the old way of photographing. The professional and amateur photographer comparison test was predictable. Professional composes while amateur looks. Technology advancement changed how we take photos. We don't look and feel the subject but instead through the screen of our equipment instead.

"理解只是使誤解的偏差小了一點?" 看了几遍都不明白,读了评语后,才逐渐了解。

Is it possible to produce 100 grams of garbage each month? Yes, to live with a zero-waste life, you and your partner in crime need to be discipline, have access to cheap locally produced natural food, and living away from busy city.

Why you should join the analog social media? Part of the digital minimalism movement. Just use digital and Internet for essential tasks (works, writing, calendar, map, and others). Join a photowalk walk and have a good discussion on photography, life, or event itself. No need to upload, post, and share the photos.

Perl Module(s) Of The Week - 2019 Week 02 - Module::CoreList

One of the issue when using Perl is the abundant list of Perl's modules. Finding the right modules can be overwhelming and sometimes frustrating. Duplicating, deprecating, or abandon modules is typical situation for a programming language which is 31 years old. Hence, which recommended Perl's module should you uses then? Start with the modules that came default with the Perl installation, the core list. How? By using the Module::CoreList module.

Installation and quick check of the module.
$ cpanm Module::CoreList
$ perl -e 'use Module::CoreList'

Now, let's write some code (``) to list out all the core modules that came with Perl 5.29.6.
use strict;
use warnings;
use feature qw|say|;

use Module::CoreList;

say $_ foreach sort @{[Module::CoreList->find_modules(qr/.*/i, 5.029006)]};

Running the code and show the first ten results.
$ perl | head

So far so good. But do we need to write some code in order to make any query? No, there is a console utility, corelist that will do that. For corresponding command almost similar to our Perl's code before this.
$ corelist -v 5.29.6 | head

The following modules were in perl 5.29.6 CORE
Amiga::ARexx                                 0.04
Amiga::Exec                                  0.02
AnyDBM_File                                  1.01
App::Cpan                                    1.671
App::Prove                                   3.42
App::Prove::State                            3.42
App::Prove::State::Result                    3.42
App::Prove::State::Result::Test              3.42

Now some code reading. What interesting stuff can we learn from reading the source code of Module::CoreList?

(1) All the data, for example, Perl's version, starting from Perl 5 was hard-coded as large hash (see the `%released` hash).

(2) To prevent duplication, the changes (see `delta_from`, `changed`, and `removed` hash) of modules for each Perl version were stored as delta hash (see `%delta` hash).

(3) These use of `@_` pass through from one subroutine to another subroutine as shown below. See the `first_release_raw` subroutine.
sub a { say @_; }
sub b { &a; }
sub c { &a(); }
sub d { a(@_); }
sub e { &a(@_); }

b 1, 2, 3; # 123
c 1, 2, 3; # nothing is printed
d 1, 2, 3; # 123
e 1, 2, 3; # 123

(4) The END block is not a subroutine but a block of code that executed after all codes have been ran and before the Perl interpreter exited.

How about source code from corelist?

(1) *nix piping in Perl. See the example below.
    my @bundles =  map { $_->[0] }
                  sort { $b->[1] <=> $a->[1] }
                   map { [$_, numify_version($_)] }
                  grep { not /[^0-9.]/ }
                  keys %feature::feature_bundle;

Research Paper to Read: (2018) Minimal water volume for intensively producing male Siamese fighting fish (Betta splendens Regan, 1910)

Source: Research Gate.

(1) 150 mL water volume within 2 - 9 cm depth should be the minimum and optimum water volume to rear individual male Siamese fighting fish.
(2) Jar the fish when it reaches 1.5 months old (6 weeks) and sell it at 4 months old (16 weeks).

Why this paper?
Betta fish (B. splendens) is an aggressive and territorial tropical fish. To defend its territories, a Betta fish will flare its gill and spread its fins. Furthermore, it will bite its intruder. Therefore, upon reaching adulthood, the male Betta will need to be separated and jarred into separate and smaller container. However, a Betta fish spawn, on average, contains few hundreds of fries. Hence, to fully utilize available spaces and giving the Betta fish the optimum growing environment, what is the minimum water volume or container size that can achieve this? Our observation is most breeders will use several cost saving ways to jar individual male Betta fish. These consists of using recycle mineral water bottle, thin glass alcohol bottle, or drinking plastic bags.

Material and Methods
This is a randomized design experiment of 5 water treatments and 15 replicates. First, one-month old solid-red male Siamese fighting fishes were purchased and individually acclimatized in cylindrical plastic breakers (7.5cm diameter x 12.5cm height) of water volume of 250mL for 2 weeks (not sure why?). Then, 15 fishes (n = 15) of similar size (0.97 ± 0.01 g initial body weight)were evenly and individually distributed into 5 water volumes of 100, 150, 200, 250, and 300 mL glass aquaria (3.5cm width x 8cm length x 20cm height).

Breeding conditions for 8 weeks or 2 months as follows:
(1) Commercial floating pellets (10% moisture,  46% crude protein, 6% crude lipid, 5% crude,
fiber, and 12% crude ash).
(2) Feeding done twice daily (08:00h and 17:00h) at 2% of body weight.
(3) Photoperiod of 12h (light) : 12h (dark)
(4) Uneaten excess diet were siphoned after 30 minutes after feeding.
(5) 80% water changes with dechlorinated stock water within 3 consecutive days.

Since it's too long and quite complicated (I don't really understand it), I skipped the part on what measurements and tools used.

Only the results for water quality and overall growth were discussed here.

Since leftover food were siphoned, the only contributing factor to water quality is the ammonia level due to excreted water by the fish. The lower the water volume, the higher concentration of ammonia level and lower pH level as shown in table below for water volume of 100mL.

Large water volume (300 mL) will lead to bigger fish growth (standard length) and at the same time, allows more space for increase movement (like bubble nest making) within the container, and thus, low weight gain.

How big is 150mL? The video below will give you some idea. Should you use this minimum water volume for optimum growth? Depends. If you have large quantity of fishes, limited spaces, and plenty of time for water changes, then this should be the right option. If not, use the largest water volume possible so less than frequent water changes. When breeding and rearing Betta fishes, water changes is the only task that consumes most of your time.

Further Questions
(1) Will plastic bottle instead of glass aquaria have any significant effects on the experiment?
(2) When do we start to jar the male Betta fish? Is it 1.5 month of age when it starts to show aggression behaviour or when it reaches certain size of 2.5cm?
(3) Will there any significant changes if the water were treated with Indian Almond leaves?
(4) Is there any significant impact to the result if these fishes were fed with live food sources?
(5) Large water volume means less frequent water change. Is there any impacts on frequency of water change to the result?

UMT MOOC: Ornamental Fish Culture - Topic 2: Biology of Ornamental Fish - Goldfish

Continue from previous post and the last series of topic 2 installment.

The Goldfish is one of the most common fishes kept as pet. There are so many species and varieties, which one should you pick? Personal recommendation is go for Shubunkins.

Goldfish Species
Ryukin. Key characteristic is a hump in the shoulder area (top).

Liaohead. Key characteristic is large hood or "wen" but without dorsal fins as compare to Oranda.

Oranda. Key characteristic is bubble-like hood called "wen" that needs trimming if needed.

Celestial Eye. Key characteristic is telescope eyes that turned upwards. I'm not sure we've seen this in any aquarium stores. I'm not sure why this deformation and popularized.

Shubunkin. Key characteristic is single-tailed and pattern known as "calico". Due to its similarity to Koi fish, people may mistaken it for Koi. If you like to keep Goldfish as pet, this species would be a better choice. At least, the species looks like a normal fish instead of mutated bloated fish.

Pompon. Key characteristic is it has nascal outgrowth, similar to Lionhead or Oranda. Unfortunately, we never see one before in any aquarium shops. Perhaps we miss it.

Bubble eye. Key characteristic is two large fluid-filled sacs. Similar eyes to Celestial Eye but with large sacs. We're wondering why this Goldfish ever been popular in the first place. For us, this is a worst deformation and such species shouldn't been breed in the first place.

UMT MOOC: Ornamental Fish Culture - Topic 2: Biology of Ornamental Fish - Primitive/Jurassic Fishes

Continue from previous post.

Below are the list of ornamental fish which have primitive or jurassic looks.

Arowana. These sought after species which are found in local aquarium shops are typical from the species of Asian Arowana. Arowana in general are surface feeder, aggressive, mouth breeders, and excellent jumper.

Arapaima. Considered the largest tropical fish in Amazon river. Similar to Arowana but much bigger and uglier. Definitely have the primitive or jurassic looks and aggressiveness. We have been to quite a few aquarium shops but can't recall we've seen any of this species.

Peter’s Elephantnose. One of the weirdest looking fish, looking like an angry penguin. We only saw this once in the aquarium shop, can't recall which shop. Some hobbyist put this together with Arowana just to "spice up" the tank.

Butterflyfish. This is referring to African Butterflyfish, Pantodon buchholzi. As the name implies, the fish have a pair of butterfly-like fins even though it's quite ugly. Never seen this in any local fish stores.

Knife fish. Body shaped like knife and I remembered I even caught one when I was young. The local aquarium shops carry a few species like Black and Clown. If you like fish with odd shape, then this should be your choice.

Gar. Like a thinner version of Araipaima and the fish version of aligator. Not sure we have seen this here locally.

Bichir. Looks like a dragon or reptile in the water. We're not sure why this fish was ever considered as pet? Saw quite a few before but not really appealing as the boring brownish colour and less majestic compare to other fishes.

Sturgeon. The species we're discussing here is Acipenser. This is probably the most mean looking predator fish of the list. Is like the fish is wearing an armor. Never see this in any aquarium shops here.

Paddlefish. Another fish that should be in pond instead of aquarium. Looks like a paddle stuck to the front of the fish. Definitely looks like a primitive fish.

Lungfish. A fish that can hibernate for a few years. Not sure this is a suitable aquarium fish.

UMT MOOC: Ornamental Fish Culture - Topic 2: Biology of Ornamental Fish - Famous Species

Continue from previous post.

Famous Species
These are common ornamental fishes found in most large aquarium shops. Not all aquarium shops (these are really just pet shop) will carry these fishes.

(1) The Tetra. One of the most popular fish in aquarium shop. Small size with bright colours, predominately red. The Neon Tetra and Cardinal Tetra are the popular beginner fish for those who are ventures into aquascape. Also, a good fish to put into the community tank. As Tetra is egg-scatter, it's easy to breed a large spawn of Tetras. Hence, most of these fishes were sold at around MYR1 till MYR2. We have kept a few for our self for quite a few months before the outbreak of the tank due to lack of maintenance.

(2) The Barbs. Body size is larger than Tetra. The species is aggressive, active, and fast swimmer. If you like to observer a a group of fast swimming fish during feeding time, the Barb is the right fish for your. Colour-wise, mostly gold and silver with some black and red highlight. Similarly, is a egg-scatter, hence prices for Barbs are roughly less than MYR10, depends on species. We have a few Rosy Barb before but need to feed it well to retain the colour and not really a good fish for community tank.

(3) The Catfish. Not what we consider as pretty and colourful fish. Mostly are blackish and brownish in colour. Larger one are treated as good protein food source. Interesting aspect of this type of fish is it has no scale with bony plates and barbells. As these are bottom feeder, most fishkeeper put a few smaller size Catfish such as Corydoras to clean up the aquarium. The local here like to call it DBKL (our local city hall which involved with clean up with city). Price wise, roughly less than MYR15. We've a few before but I can't remember the exact species we have.

Loaches. Bottom feeder, active, and fast swimmer. Not a popular fish in local aquarium shops, only saw a few Clown Loaches.

Livebearers. As the name suggested, these fishes carry its fry within the body. Mostly are Guppies, Mollies, Platies, and Swordtails. Another common and cheap pricing fishes in aquarium shop. Guppies are way more popular compares to other livebearers. We have all these before but not really our type of fishes. Except maybe Guppies, the others are surely lacking in aesthetic, from our point of view.

The Cichlids. These includes Angel, Discus, Parrots, Ramirezi, and Cichlids (African Cichlids). The last one is aggressive and not a good tank mates. We always mistaken African Cichlids as saltwater fishes instead due to it similarity in term of colours. These are mouth-breeder, which you can't get a big spawn. Hence, pricing is higher compare to other fishes.

The Labyrinth. Basically an air-breathing fishes. Immersely popular fishes in every aquarium shop. You will surely find at least one species, especially Betta (Siamese Fighting Fish) and Gourami (Dwarf Gourami). Pricing wise, Gourami (less than MYR2) is way cheaper than Betta (MYR 3 till MYR 70). We have quite a few of these in our community tank. Have to be quite careful not to overfeed as a few succumbed to Dropsy.

Crayfish. This is just large freshwater shrimp. Saw quite a few aquarium shops carried this type of fishes. Invasive species and not supposed to be throw into your local rivers. Depending on size, not a good tank mates for other fishes. We were thinking about adding a few crayfishes (as our bottom feeder) to our community tank but gave up that idea as this can be easily replaced by Ghost Shrimp, which was way way cheaper.

UMT MOOC: Ornamental Fish Culture - Topic 2: Biology of Ornamental Fish - Body Profiles and Spawning Behaviours

The main purpose of the topic is the categorization of ornamental fish based on its biological aspect in term of body profile and fish spawning behaviour.

Body Profiles
(1) Normal shape.
(2) Torpedo shape.
(3) Club shape.
(4) Hatchet shape.
(5) Worm shape.
(6) Disc shape.
(7) Spindle shape.
(8) Boat shape.

Spawning Behaviours
(1) Bubble-nest builder. These type of fishes build a bubble nest using leaves or any floating fragments like plastic bag and artificial nylon line (I believe is those that used for fruit wrapping). The pair of fishes mated and fertilized eggs are collected into the bubble nest. Known species are Betta and Gourami.

(2) Egg-scatterer. Spawning occurred either in pair or in group. Lots of eggs will be produced during mating and female fishes will scatter eggs to substrate, plants, artificial nets, or just float around. Depending of fish types, eggs are either adhesive (sticky and stick to plants) or non-adhesive. Once spawning is done, the parent fishes will not look after the eggs and will eat the eggs if possible. Known species are Danios, Rasbora, Barb, Cyprinus, Tetras, Koi, and Goldfish.

(3) Egg-burier. This species lay eggs in the mud or sand. Hatching can be postponed due to dry season and reactivated back one there is water. In other words, you can buy these eggs and hatch it later. Known species are Pearlfish and Killifish.

(4) Egg-depositor. This species deposits its eggs in quiet and safe places like wood, plants, glass, rocks, PVC pipes, and rubber cones tower. Known species are Angle, Discus, Clownfish, and Damsel fish.

(5) Live-bearer. Breed like mammals where the female fish carried the juvenile fishes in its stomach and give birth when ready. Known species are Swordtail, Molly, Guppy, Platy, Four-eye, and Piketop fish.

(6) Mouth-brooder. The male or female collects fertilized eggs into its mouth for incubation. Known species are Cichlid and Arowana.

This Week I Learned 2019 - Week 01

Happy new year 2019! Another year, another new TWIL post.

For those who miss out the previous post of the series, check out the last TWIL post of previous year or the whole year review. As usual, go through some legacy TWIL posts as well.

What else I learned this week in separate posts? First, ornamental fish culture in terms of overview, industry, popular tropical fish species through our local online MOOC. Second, the literature review of the paper on the effect of salinity and diet on Betta fish growth and survival. And lastly, the start of Perl Module(s) of the Week (plMOTW) series which we review the Data::Money Perl's module.

What is a mental model? According to Wikipedia, mental model "is an explanation of someone's thought process about how something works in the real world." In other words, a mental model is a systematic thought process that helps you to make better decisions. There are several list of mental model catalogues, Gabriel Weinberg's list (for Anki as well), Kent Beck's list, Slava Akhmechet's list, and Farnam Street's list. Similarly, there are cognitive tricks or  "brain hacks" that you can use on daily basis to manage your life. Contrary, the discussion on these "brain hack" is more philosophical rather than systematic to approach any issues. Nevertheless, good mental exercises for anyone, especially those on writing which I should adhere strictly. This reminded me of a research on when is the best time to write.

What is the morning writing effect? (via HN) Discussion and research on what is the best optimum hours to write. Not surprising, morning is the preferable schedule but because for those who were interviewed, they worked as a full time writer or writing is a major part of their works. Hence starting to work or write in the morning is obviously answer. Discussion at Reddit seemed to have different opinions. For those who have a day job and write casually, night time is the most suitable hours, where everything have slow and quiet down. The discussion on best hours to write relates to our sleep hours and quality.

What is circadian rhythms? It's our internal biological clock responses corresponding to external environment factors like light, temperature, and others. Your health and productivity will be affected if there are any disturbances in your circadian rhythm, for examples, jet lag or blue LEDs light (mobile phone or PC) which affects our sleep (secretion of melatonin hormone which regulates circadian rhythms) leading to drowsiness. To achieve good health and improve our quality of life, not only we need to eat well and exercise adequately, we also need to sleep satisfactory. Does fishes have circadian rhythms? Not really but there was a research suggesting that fishes may have.

Perl Module(s) Of The Week - 2019 Week 01 - Data::Money

Since this item was on my to-do list for quite some time and this is the first week of the new year, might as well proceed ahead and do it. Inspired by Python Module of the Week (PyMOTW), I will start a series of weekly blog posts to review and discuss any interesting Perl module(s) that caught my attention. Write up mostly will be on some code example, issue encounter, and what can we learn from the code, as in code reading.

Our Perl module of this week is Data::Money, which allows us to perform math operations on different currency in an object manner and let us understand how operator overloading works in Perl. Furthermore, this is a good example to showcase the actual implementation of PoEAA's Money class design (there are actual four Money class designs exists), which is a rather simple approach which does not allows multiple currencies operation. Nevertheless, an actual production ready implementation.

Installation and quick check of the module.
$ cpanm Data::Money

It seemed in latest Perl version (v5.28.0), the dependant modules, Locale::Currency and Locale::Codes will be removed from Perl core distribution.
$ perl -e "use Data::Money"
Locale::Currency will be removed from the Perl core distribution in the next major release. 
Please install it from CPAN. It is being used at /usr/local/lib/perl5/site_perl/5.28.0/Data/, line 27.
Locale::Codes will be removed from the Perl core distribution in the next major release. 
Please install it from CPAN. It is being used at /usr/local/lib/perl5/5.28.0/Locale/, line 22.

To remove the warnings, we have to install Locale::Currency manually.
$ cpanm Locale::Currency
$ perl -e "use Data::Money"

Let write some code (save as file ``) that create the new Money object or data type. `MYR` is the currency code where `MY` is two digits country code for `MalaYsia` and `R` is the name of the currency, in this case, `Ringgit`.
use strict;
use warnings;
use feature 'say';

use Data::Money;

my $price = Data::Money->new(value => 1.2, code => 'MYR');
say $price->as_string;
say $price->stringify;

Running the code will give us the same result twice. `RM` is the currency symbol that replaced our previous used `$` symbol.
$ perl

Let's look at these two subroutines, `as_string` and `stringify`. First, `as_string` is an alias to `stringify` subroutine. To create an subroutine alias in Perl, we will need to use typeglob (hence, the asterisk notation) to manipulate the Symbol Table, which stores all the variables in a package.
*as_string = \&stringify;

Second, as the name implied, `stringify` is typical subroutine naming convention for stringification in Perl, to convert an object into string or context of string. This is done through `overload` package as shown below, where it's implemented through anonymous subroutine. The subroutine will be invoked whenever the blessed package was called in a string context. You can read this tutorial for a sample working stringification using classical OOP way.
use overload
    '""' => sub { shift->stringify };

Research Paper to Read: (2010) Growth and Survival of Siamese Fighting Fish, Betta Splendens, Larvae at Low Salinity and With Different Diets

Source: Research Gate.

(1) Combination of natural live foods (Chlorella sp., Rotifers, and Artemia nauplii) ensures good growth rate.
(2) Salinity of 5 ppt using non-iodized salt prevents the Piscinoodinium sp. parasite which is the causative agent of velvet rust disease.

Why this paper?
Betta fish (B. splendens) is one of the most popular ornamental fish and it's known to be easily breed. While there are numerous information (websites, books, and videos), most of these information are experiences gained through casual observation rather than scientific research. Two questions were raised during our breeding projects, how can we accelerate the growth and increase the survival rate of our Betta fish larvae (still have yolk-sac and unable to feed themselves) and later as fries (free swimming and can feed themselves)? This paper was written to answer both questions by investigating the best nutrients for the Betta larvae and fries for the first 15 days.

Materials and Methods
The larvaes and fry were the results of a pair of sexually mature (not sure how many months) B. splendens (not sure which species). The pair was fed twice daily (anytime) with flake food and live brine shrimp. Larvae were jararred at 3rd day into 18 round-bottom glass flasks (2L) where each flask contained 10 larvae. These were duplicated into 3 sets as follows:

(1) Treatment: Natural, Salinity: 0 ppt
(2) Treatment: Natural, Salinity: 5 ppt
(3) Treatment: AD + LA, Salinity: 0 ppt
(4) Treatment: AD + LA, Salinity: 5 ppt
(5) Treatment: SDLA + AD, Salinity: 0 ppt
(6) Treatment: SDLA + AD, Salinity: 5 ppt

Culture condition of the larvae as follows:

(1) Salinity was obtained by adding non-iodized cooking salt (aquarium salt should works as well) in portion of 5g/L in distilled water (all minerals were removed).
(2) Temperature set to 26C. (How do they maintain the temperature constantly?)
(3) Photoperiod, 12h light : 12h dark.
(4) 80% water changes on daily basis.

Below is the exact daily rations grouped into three stages of the larvae or fries lifecycle of 15 days. Larvae were fed four-times per day in a 4 hours intervals (0800, 1200, 1600, and 2000h).

Details of the diet with photos (from Wikipedia) as follows:

(1) Freshwater microalgae Chlorella sp.

(2) Rotifers (Brachionus rotundiformis, B. plicatilis "S type").

(3) Artemia nauplii (Brine Shrimp).

(4) Semi-purified microbound formulated diet (particle size 250–450 μm) with ingredients of (37.4% lipids, 46.2% crude protein and 5.6% ash)

As the table below have shown, natural diet yielded the best survival rate and second in growth rate. The total average length of the fries is more precise to the observed and non scientific measurements of the Betta Growth Table.

Why natural live food diet compare to formulated diet gave the optimum survival rate? Betta larvae or fries naturally eat moving living organisms instead of lifeless static food pellets. Furthermore, 100% survival rate was achieved with natural diet and non-iodined salt (5ppt salinity), which prevent the Piscinoodinium sp. parasite which is the causative agent of velvet rust disease as shown in figure below.

This is another photo (source: Wikipedia) showing the actual infection of the parasit.

I'm not sure why the diet of LA + AD with salinity cultured the largest growth length. Unfortunately, this was not discussed in the paper or did I miss or misunderstood it?

Further Questions
(1) When is the sexually mature age for both Betta male or female fish?
(2) How does the frequency of daily feeding (2, 3, or 4 times) influences the larvae and fries growth?
(3) How to calculate the salinity of 5ppt corresponds to the container size?
(4) How does photoperiod influence the growth, survival, or reproduction?
(5) How many percent of daily water changes needed?
(6) Why we need to perform daily water changes?
(7) Does distilled water essential for reproduction, growth, and survival of larvae or fries?
(8) Does the percentage of protein in formulated diet influences the growth and health?
(9) What is the range of salinity level for breeding Betta?

UMT MOOC: Ornamental Fish Culture - Topic 1: Popular Tropical Fishes

Further elaboration on previous post.

Below are the list of popular tropical fishes grouped by family. I've created a separate blog post to further elaborate more details on each group of fishes. Since there is no source on how this information was collected and tabled, I assumed it's from Department Fishery of Malaysia. Googling around, I've found two large fish farms, Sanwa (SW) and Qian Hu (QH) in Malaysia and did a comparison of types of tropical ornamental fishes provided by these fish farms against the original list (OL) in the slide. Based on my initial comparison, it seemed the OL is not comprehensive and some fishes were put into the wrong category instead.

OL: Barb, Danio, Goldfish, Koi, Sharks, Rasbora
SW: Algae Eater (3), Barb (30), Danio (24), Goldfish (30), Koi (10), Loaches (34), Rasbora (21)
QH: Algae Eater (5), Barb (43), Danio (26), Goldfish (45), Koi (9), Loaches (26), Sharks (7), Rasbora (25)

I'm not sure why both Goldfish and Koi was put into "cold water" category in their catalogues.

Cobitids / Cobitidae
OL: Loaches, Botia, Ghost Fish
SW: Loaches (0), Botia (0), Ghost Fish (0)
QH: Loaches (0), Botia (0), Ghost Fish (0)

Loaches can be categorized into other families. Both farms don't carry this family of fishes.

Cypinodontidss / Cyprinodontidae
OL: Kili , Asst. Fish, Pleacotomus, Betta, Flying Fox, Blood Parrot
SW: Kili (0), Asst. Fish (0), Pleacotomus (0), Betta (0), Flying Fox (0), Blood Parrot (0)
QH: Kili (0), Asst. Fish (0), Pleacotomus (0), Betta (0), Flying Fox (0), Blood Parrot (0)

I believe the list is wrong. Betta and Blood Parrot shouldn't be put here.

OL: Pelaga, Gouramy, Corydoras
SW: Pelaga (8), Gouramy (42), Corydoras (0)
QH: Pelaga (19), Gouramy (42), Corydoras (0)

Again, Corydoras shouldn't be under the family here. Pelaga is Malay name for Betta fish.

OL: Molly, Guppy, Planty, Swordtail, Mino
SW: Molly (8), Guppy (14), Platy (15), Swordtail (11), Mino (0)
QH: Molly (105), Guppy (39), Platy (100), Swordtail (47), Mino (0)

I'm surprised that QH have so many species of Molly, Platy, and Swordtail.

OL: Tetra, Silverdollar, Putter Fish
SW: Tetra (48), Silverdollar (0) Putter Fish (0)
QH: Tetra (58), Silverdollar (0), Putter Fish (0)

Tetra is the most popular fish here. You can find it in all aquarium shop. I suspected that "Putter Fish" is actually "Puffer Fish".

OL: Angel, Oscar, Discus, Chichlid, Ramaresi
SW: Angel (20), Oscar (0), Discus (24), Chichlid (96), Ramaresi (12)
QH: Angel (38), Oscar (5), Discus (23), Chichlid (61), Ramaresi (0), Blood Parrot (12)

OL: Pearl, Arowana, Black Arowana, Silver Arowana, Rainbow Fish
SW: Pearl, Arowana (14), Black Arowana (0), Silver Arowana (0), Rainbow Fish (0)
QH: Pearl, Arowana (14), Black Arowana (0), Silver Arowana (0), Rainbow Fish (0)

Callchthyids / Callichthyidae
OL: Catfish, Suler Mouth
SW: Catfish (36), Suler Mouth (0)
QH: Catfish (0), Suler Mouth (0)

UMT MOOC: Ornamental Fish Culture - Topic 1: Introduction to Ornamental Fish Industry

Continue from the overview.

What is ornamental fish? As the word "ornamental" described as "decorative", any fishes that were breed as non-food source rather than cosmetic (form over function) or rarity can be considered as ornamental fish. For example, certain fish like Grouper can be cultured and reared as both food or ornamental purpose. Also, Albino fishes (mutation is genetic where the lost of coloration) are selectively breed and kept as ornamental fishes due to its rarity.

History of the Ornamental Fish Industry
The practice of fish keeping is believed to be started in Song dynasty. Colourful carp (the ancestry of  both Goldfish or Koi) were breed as popular aquatic pet in garden pond, a part of architecture style of Chinese garden. The fish keeping practice was spread to Japan in 16th century, and Europe in 17th. Only in 19th, the hobby of aquarium fish keeping experienced a surge of interest due to development of aquarium technologies especially the water temperature control system (e.g water heater). Thus, the primary market for ornamental fish is western world, which have higher purchasing power.

Economic Importance
In ornamental fish trading market, fresh water fishes covers 90% and marine fish accounts for 10%. In 2015, imports to EU countries, US, China, and Australia were around 78 million pounds. Although Malaysia was a top ten (7th in 2015) ornamental fish producers or exporters, it only contributes 13 million pound to the market value (compare to our neighbouring countries, our exports was relatively too small). This is why, most fishes in local aquarium stores were either rejected or secondary quality batch. Good quality fishes were already exported due to higher market value. If you want good quality fishes, might as well source directly from local breeders or fish farms instead.

Malaysia’s Ornamental Fish Industry
The industry was started around 1950s, mostly in Johore state and exclusively on collection of wild species. Only in 1980s, 18 farms were started in Johore and slowly expanded to 135 farms in Perak, Selangor, and Penang. Later on, in 1993, 336 farms and also aquatic farms in Johore. In year 1997, 400 farms have been recorded with 90% ornamental fishes and 10% aquatic plants. And in year 2016, there were 597 ornamental fish farmer and 11 aquatic plant farmers. It should probably expands to more states these days due to advancement of Interweb and logistic (transhipper).

Factors of Ornamental Fish Industry Development
What contributes to the growth of such industry in Malaysia? First, year long tropical climate and variety of tropical fishes found locally. Second, logistic infrastructure connecting different rural areas and especially those farms in Johore which are near to Singapore. Third, government supports through Department of Fishery Malaysia by conducting researches, initiatives, training, and funding. Just a side note, no all tropical fishes were treated equally, focus was on selected tropical fishes with high market values. Fourth, as mentioned, the close proximity to Singapore, which is Malaysia's largest importer.

Ornamental Fish Species
Interview session with Mr. Chew, the second generation of Chew Thean Yeang Aquatic and Pets store owner. His father started this tropical fish business since 1963 selling river fish, Guppy, and Tubifex Worms in 1965. (wonder how the tropical fish hobby looks like in those days?). The aquarium shop have been opened in Swatow Lane, GAMA Supermarket (1982), and later, independent shop lot next to Gamma Supermarket. They started exporting fish (they have their own fish farms) to Singapore in year 1997 since then, they expands this to Thailand, Indonesia, Japan, Hong Kong, Europe, and others. In year 2004, they moved the main shop to middle of Georgetown. Like all aquarium shops in Malaysia, it became a one-stop pet shop stores with 50 thousands tropical and marine fishes (300 species) based on Europe advanced filtering system. (Not sure about filtering system here). Like all aquarium shops, these shops will evolve slowly to include other pets as well. Perhaps profit margins is higher compares to fish keeping. Cats and dogs do live longer and easier to take care of. According to him, best selling fishes are Koi, Tetra, and tropical fishes (didn't specify any names).

Below are the popular tropical fishes (categorized by group) from the slides. Not sure where is the source of data (there is no link to any source).

Cyprinids. Barb, Danio, Goldfish, Koi, Sharks, Rasbora.             
Cobitids. Loaches, Botia, Ghost Fish.
Cypinodontidss. Kili, Asst. Fish, Pleacotomus, Betta, Flying Fox, Blood Parrot.
Anabantids. Pelaga, Gouramy, Corydoras.
Poecilids. Molly, Guppy, Planty, Swordtail, Mino.
Characins. Tetra, Silverdollar, Putter Fish.
Cichlids. Angel, Oscar, Discus, Chichlid, Ramaresi.
Osteoglossids. Pearl, Arowana, Black Arowana, Silver Arowana, Rainbow Fish.
Callchthyids. Catfish, Suler Mouth.

Secondary Supporting Industry
This is how most aquarium shop or pet shop making money. As these products or services do not need high maintenance. For examples, tanks, aquarium accessory, pebbles, fish foods, fish plants, fish medication, water quality management, aquascaping, and transportation.

Problems Faced by the Industry
Several problems like first fish diseases, export facilities, uncontrolled production, and invasive species problems.

UMT MOOC: Ornamental Fish Culture - Overview

The recent movie release of Aquaman piqued my interest in Fishery and I was pleasantly surprised when I found this UMT MOOC on Ornamental Fish Culture, more so from our local university, University Malaysia Terengganu (UMT). UMT is one of the leading maritime (navigation or commerce on the sea) and marine science (the study of ocean) university in Malaysia. As the name of the university suggested, this university is located in Terengganu, a state in the northern part of Malaysia. I applauded the effort to push this course as MOOC as this is a niche subject and the location of the university is located far north. Based on my initial impression, the university was pushing hard in providing good MOOC as seen from its You Tube channel (although the auto-generated transcript provides another form of entertainment).

The main purpose of this course is to expose learner on the science and industry of ornamental fish in term of management, development, breeding, and rearing. If you're an amateur fish breeder, it's good to learn the science behind fish breeding instead of multiple trials and errors without any good sense of directions. Our goal is, hopefully in future, we can breed those wild Bettas (endangered species if possible) successfully or any tropical fishes of our liking.

The course syllabus as follows:
  1. Introduction to ornamental fish industry
  2. Biology of Ornamental Fish
  3. Quality Characteristic Determining
  4. Nutrition of Ornamental Fish
  5. Ornamental fish breeding
  6. Selective Breeding and Biotechnology
  7. Seed Production of Ornamental Fish
  8. Principles of water quality managements
  9. Culture systems
  10. Aquarium decorations
  11. Disease and Treatment