Tropical Aquarium Fish

Corydoras paleatus was introduced in aquaria in 1876. The first reproduction in aquarium was realized in 1878 by Carbonnier. The natural environment is in south-east Brazil, from La Plata to Argentina, where it lives in slow motion waters.

The male reaches 5 cm length and it has a higher and sharper dorsal fin than the female. The body of the male is more slender in comparison with the female, especially in the spawning period. The female is burly and larger, reaching 7 cm length. The body coloration is grey-green, with a ochre abdomen. On this background there are some dark colored spots and point, which can be blue or green-violet (depending on the light angle). The fins are yellow with small dark colored spots lines.

It is a friendly fish and it doesn`t request any special water chemistry. That`s why it can be easily bread in a common aquarium. Corydoras eat anything, from living food to dry food but only from the bottom of the aquarium. They prefer tubifex and daphnia. Because they feed by grouting the sand, this will have a smaller granulation and no sharp edges. If these things are not respected, their mustaches will be damaged. After that, the bacteria from the aquarium may attack the new formed wound. As a remedy, we`ll use a better filtration system (especially if we feed them much and the bacteria can`t annihilate the decomposing materials) and we`ll change the ground with a small granulation sand. If the mustaches are not too damaged they`ll renew. They can live at temperatures between 18-28° C. Frey even mentions the fact that it`s better to keep the fish outside till frost time. The optimal temperature is 23° C.

Hoplosternum thoracatum was introduced in aquaria commerce in 1911. It`s native from the north of South America, Trinidad and Martinique. The local name is atipa. Even if in Romania it was introduced and reproduced after 1980, it has a good reputation contrary to its size of 15 cm length.

The body plaques join the back plaques. The body is strong; it has 2 mustaches pairs on the superior maxillary. The tail is a little concave and the adipose fin has a support thorn. The maximum length is 20 cm. The background is colored in grey-brown, with a darker back and white abdomen (except the spawning period). On the body it has big brown-black spots which can form a line on the flanks. The fins are grey-yellow and they have black points. On the tail there is a dark colored line.

At the age of 6 months the sexual difference is obvious. The male has longer pectoral fins than the female. The female has a larger body diameter. Usually the abdomen is colored in white, but in the reproduction period the male has a dark spotted abdomen. These fish start their sexual activity after the age of one year.

It doesn`t have special needs for the water chemistry. The spawning can take place at a temperature of 18° C, and they eat almost anything from the bottom of the aquarium. In general, they need large aquariums (about 120 liters), rich planted and with many hiding places.

Hoplosternum thoracatum builds a bubble nest at the surface of the water, under a support which can be a leaf, a plaque of glass or a polystyrene portion. Ruda Zukal mentioned that he obtained the best result with setting a black piece of plastic on the inferior part of the support. From the nest building start point, the male becomes very violent and it attacks even when we feed it. The bubble nest building can last 2 days, even 1-2 weeks. For stimulating the nest construction it`s recommended to put some oak tree leaves on the bottom of the aquarium. Normally, for reproduction they are kept in couples, sometimes 2-3 females for a male. The male will spawn with every female after a short break. The reproduction aquarium can be planted or not and can have ground or not.

Ancistrus cirrhosus is part of the Loricariidae family. It`s better to breed them in pairs or with night active fish as they are. Their feeding request vegetal food, but thy can also be fed with living food or tablets. The living food, daphnia, will be administrated frozen.

The water has to be normal, normal illumination but with many floating plants at the surface of the aquarium water. The optimal temperature is 23° C. They live on the bottom of the aquariums. Their natural environment is in the east and north-east of the tropical area in South America, in Guiana, Trinidad, Amazon River and Rio Paraguay.

The front part of the body is oblate. On the top of the mouth they have ramifications (horns) which can fork. The dorsal fin is high, the first ray is strong, and on the pectoral fins it has very strong spikes. The tail has strong rays in the superior and inferior parts. Between the rays the tail is oblique. This ancistrus can reach 14 cm length. The coloration is dark olive-brown to black; the abdomen is grey-green to brown-grey. On the fins it has dark colored spots and at the beginning of the dorsal fin it has a big black spot.

Usually the Welse family is improper considered a `cleaner fish` family with reduced water and food needs. Most of the beginner breeders have the false impression that these fish feed with other fish rests. This impression is wrong because their needs are at least equal to the other fish, if not superior. It`s true that they are used as complementary fish together to other fish more colored, active and popular. This bad reputation, that they are cleaners, comes because of the fact that they are bottom fish with their mouth situated in the lower part, and they can only eat from the ground. If they feed from the middle aquarium water they do it rarely and without ability. It`s known that Welse fish can survive in a not aerated aquarium because they have an abdominal auxiliary breathing system. The entire Welse family is sensitive to the water chemistry. Concentrations of elements that for other fish are inoffensive can harm these fish from Welse family. They are new fish in aquaria, recently introduced in aquariums. Their reproduction in captivity hasn`t been made since long time, only recently, it`s the case of Dianema longibarbis, Ancistrus, etc. Every sheat fish family contains lots of fish with different behaviors. In aquarium it`s better to have fish for every level of water: surface, middle and bottom. In this last category we include the Welse fish.
Except the poles, they are spread all over the globe. In general they are freshwater fish, but there are some saltwater species too. There are about 2000 species of Welse, in South America you can find about 1200 including the welse covered with bony plates. They prefer the bottom of the aquarium where they search for the food using their mustaches. In the natural habit, they can be found in rivers, lakes and waters without oxygen. There are some species which bury themselves in the mud waiting for the rainy season. That`s why when we set up an aquarium we have to be careful to satisfy at least the minimum of their needs. We`ll have to create places for hiding, caves, roots and especially spaces for resting during night (platforms near the surface of the water). Most of the Welse species are more active during night, that`s why we have to be careful with their feeding (example: Loricariidae family). Some other species have strange ways of swimming (Synodontis swims upside down).