Saturday, June 21, 2008

Black Widow Tetra

Data Sheet

Scientific Name: Gymnocorymbus ternetzi
Other Names: Black Tetra, Black Skirt Tetra
Adult Size:2.5 inches (6 cm)
Lifespan:5 years
Tank Level: Mid Dweller
Minimum Tank Size:10 gallons
Diet: Omnivore
Breeding:Egg Layer
Ideal pH: 6-8
Temperature: 68-78 F (20-26 C)
Tank setup: Ideally planted aquarium
Females are generally larger and have rounder body.


Growing to about 6 cm (2.5 in) total length, the black window tetra has a roughly tetragonal body shape and is greyish in colour, fading from light at the nose to near black at the tail. Two prominent black vertical bars appear just posterior of the gills.


The Black Skirt tetra is a very hardy fish that is suitable for beginner aquarists. Since it is native to subtropical waters, it will appreciate a lower temperature than what is found in most tropical aquariums. Ideally keep the temperature between 20 and 26° C (68 and 79° F).

A schooling fish by nature, black widows Tetra are best kept in groups of six or more. Due to their peaceful nature, they make an excellent community fish. FishLore noted that Black Widow Tetra sometimes nip the fins of slower moving fish, particularly those with long flowing fins such as Bettas Angelfish. However, when keep in groups of 6 of more, they tend to chase one another harmlessly and leave the other fishes alone. or

The Black Skirt tetras can adapt to a wide range of conditions, but rapid changes and extreme conditions should naturally be avoided. The aquarium should ideally include a lot of large plants.


The black widow tetra is an omnivore and will eat nearly anything it can fit into its mouth. Wild Black Skirt tetras are mainly carnivores and feed on insects, worms and small crustaceans. They do however also ingest smaller amounts of algae and plant matter. In an aquarium, it cheerfully and readily accept flake food, worms, and brine shrimp.


To breed the black widow tetra in captivity, the aquarium should ideally be densely planted with fine-leaved plants as the Black Skirt tetra is an egg-scattering species that prefers to release the eggs among fine-leave plants. The male will claim a territory during the breeding period and defend it.

Once the eggs are laid, the parents should be removed from the tank as these fishes tend to eat their own eggs. The eggs will typically hatch within 24 hours. The frys could be feed with egg yolk or newly hatched brine shrimp. As the fry grows larger, you can give them larger and larger brine shrimp.


Black Widow Tetra are prone to WHITE SPOT (Ich, ichthyophthirius). This disease is caused by environmental stress and/or cold water. It can also be caused by sudden changes in water temperature. It is a parasite resembling a grain of salt that feeds on the tissue of the fish causing irritation. It spreads through the skin and fins and will eventually kill the fish if left untreated. The mature parasite cannot be killed, nor can its eggs. It can only be destroyed in its free swimming stage after the spot falls off and the eggs hatch. This can take from 1-4 days. This is why it is important to continue to medicate for at least 3-5 days after the spots are gone. Add 1-2 drops of formalin or copper sulfate to the tank water and raise the temperature to 82 degrees (use formalin with great care as it is a cancer causing agent).

References Cited:

1. Black Widow, [Online], Accessed on 12 June 2008 [Available]

2.Black Skirt Tetra [Online], Accessed on 18 June 2008,[Available],

3. Aquatic Community [Online], Accessed on 18 June 2008,[Available],

Friday, June 06, 2008

Jinjin and Sasa Aquarium Adventure @ Hong Kong Aquarium Plaza

Jinjin and Sasa

Map of the Store

Spacious Shopping Center

unidentified plant

with more than 40 stores, there is something new at every corner

Sharks for sale

This section list the adventures of Jinjin (Me) and Sasa (my lovely wife) as we head to Hong Kong Aquarium Plaza.

Hong Kong Aquarium Plaza is located in Hong Kong Island, near
Tai Woon MTR exit B. The basement is really big and contains over 40 shops, and sells all kinds of aquarium items, from accessories, tank, gravel, to fishes and other exotic animals. It has a nice selection of marine and freshwater fishes.
Map of how to go to Hong Kong Aquarium Plaza.

Our first stop is the marine fish aquarium, and we stand amazed at the variety of fishes, star-fish and other rare marine fish available. The highlight of the tour is a huge tank containing sharks!

Clown Fish

Wide Variety Of Coral

Exotic Sting Ray

Nurse Shark

Rare StarFishes

unidentified fish. Help is appreciated

Then we visited the freshwater aquarium. There is a wide variety of freshwater fishes available here, including congo tetra, platy, guppies, discus, goldfish, koi, angel fishes, and parrot fishes.


Parrot Fish with tattoo on their body

Puffer Fish

Cute Terrapins

Tortoise Mating

This article and the pictures were from Tee, a reader.
We share your grief when the tortoise die.
Thank you very much for sharing.

Hi Eugene,

Here are some photos of my land tortoise trying to mate. The male one is on top of the female one. These photos were taken sometime in year 2006. Sadly, the female tortoise died. She was suffocated by the male tortoise. Somehow, the male tortoise tries to "bite" the female's neck. So, when they were in a bigger aquarium, the male kept trying to bite the female's neck and at one stage, I believe the female ran out of breath and died in the water.

Love kills (literally).

I was a little sad but life goes on. I buried the female tortoise.


Wednesday, June 04, 2008

Hermit Crab

Data Sheet

Scientific Name: Paguroidea
Other Names: N.A
Origin: Beaches and Sea.
Adult Size: Varies, depending on species
Social: See below.
Lifespan: up to 20 years in captivity
Tank Level:

Minimum Tank Size:
10-15 gallons recommended for small individual hermit crab. A bigger
population would require bigger tank.
Eats almost any thing - they are scavengers.
Mission Impossible.
Ideal pH:
70-75 F

Tank setup:
An aquarium with 2-3 inches of gravel or sand is ideal.


It is almost impossible to tell when they are in their shell.


Most species of hermit crabs have long soft abdomens. To protect these abdomens from predators, the crab find a shell in which it can retract its body into. Most frequently hermit crabs utilize the shells of sea snails, marine gastropod mollusks. The tip of the hermit crab's abdomen is adapted to clasp strongly onto the columella of the snail shell. As the hermit crab grows in size it has to find a larger shell and abandon the previous one.

Accordingly to Wikipedia, there are about five hundred known species of hermit crabs in the world, most of which are aquatic and live in saltwater at depths ranging from shallow coral reefs and shorelines to deep sea bottoms. For the propose of this article, I will be focusing on the land hermit crabs.


Hermit Crabs can be housed in a 10 gallon aquarium with 3-4 inches of sand at the bottom at minimum. Ideally there should be two shallow dishes for water. One of the dish should contain de-cholorinated fresh water, and the second dish should contain salt water. To prevent your crab from drowning, it is ideal that the crabs should be able to get in and out of the dishes easily. Some wood is recommended as most land hermit crabs love to climb.

Hermit crabs love company, and ideally they should have at least 1 to 2 tank mates. Where possible, provide a variety of empty shells that are slightly larger than the one your crab is currently in. Get shells of slightly different shapes and styles and opening size, though rounder openings are usually preferable over slit-like openings. Hermit Crabs can be surprisingly fussy about the kind of shell they like, and if a good variety is not available fighting may break out over the "best" shells.


Hermit crab are scavengers and cheerfully eats almost anything, from fruits, dead fish, shrimps etc. You could feed them some commercial hermit crab food daily, supplemented with assorted fresh fruits and vegetables, cereal and whole grain bread items, and small pieces of fish and meat. Also offer some pieces of cuttlebone or ground oyster shell (or even boiled egg shells) for an added calcium source.

It is essential that you clean food dishes daily, and remove
uneaten bits of food from the tank. Check for food away from the dish as crabs sometimes drag food off to eat away from the others.

While Hermit crabs are not exactly nocturnal animals, but they are mostly active at night. They do all their eating and drinking at night, so do not worry if they do not seem to be eating during day time.


Hermit crabs cannot reproduce in captivity. This can only be done on the beach and when the phases of the moon are right, and also the eggs have to be laid in the seawater. When the eggs hatch as plankton, they have to develop into a hermit crab which can take about a month.


One disease known to attack hermit crabs as well as their relative crustaceans such as lobsters, crayfish and sea crabs is the 'shell disease'. This infection has also been given a number of other names, such as 'shell rot' and 'rust spot'. It appears as dark mysterious spots on your hermit crab's exoskeleton. They are different to the much tinier freckle-like spots you see on their skin. The fungi are believed to grow on the infected hermit crab's exoskeleton whilst feeding on its chitin. Shell disease usually infects those who have an injury.

If they lose a leg or claw, there is a risk that the fungi maybe able to do its dirty work. It is also important to keep the tank very clean, to reduce the amount of bacteria growth. Also make sure that the food you are feeding your hermit crabs is safe and that there is no mould in it. Hermit crabs can catch diseases from this. The disease also attacks those who are overly stressed, the main killer of hermit crabs.

Hermit crabs get very stressed when they are overcrowded or do not have much room to move around in. This is when they start dropping legs and claws, making themselves open to diseases. Remember, in the wild, hermit crabs travel for kilometres everyday for food and shells, so it makes sense that you should provide them large enough home to walk around in. Hermit crabs are able to free themselves from shell disease through moulting and shedding the infected exoskeleton off. Just make sure you have been feeding them plenty of calcium and protein to aid them through the stressful time.

Photo Gallery:

Got a photo? Contact me

References Cited:

1. Wikipedia, Hermit Crabs, [Online], [Accessed on 4th June 2008],

2. Hermit Crab Paradise [Online][Accessed on 4th June 2008],

3. About Exotic Pets, Hermit Crabs, [Online],[Accessed on 4th June 2008],

4. Care of Hermit Crab, [Online][Available], [Accessed on 4th June 2008],

5. Shell Disease [Online],[Available], [Accessed on 4th June 2008],