GENETICS AND BREEDING OF THE Hoplosternum littorale By: Ashram Mahadeo

The Cascadura Kingdom: Animalia Phylum/Division: Chordata Class: Osteichthyes (Actinopterygii) Order: Siluriformes Family: Callichthyidae Genus: Hoplosternum Species Name:  Hoplosternum littorale *(Hancock, 1828) Common names: Clay/ Brown Hoplo, Armored Catfish, Curito, Cascadu/ Cascadoo, Atippa, Tamuata, Hassa(r), Kwi-Kwi, Quey-Quey. Can be found in Trinidad in rivers south of the Northern Range, Guyana, Suriname, Venezuela, French Guyana, Paraguay and Argentina.

Hoplosternum littorale or fondly called the by locals “Cascadoo”

Morphology and Anatomy Dermal plates in two longitudinal rows Mouth is ventral Two pairs of barbels (sensory organ) Gills are underdeveloped Gut is highly vascularized Reduced eyes Reduced swim bladder Vascularised gut-extracting oxygen from gulped air. Respires bimodal Reduced swim bladder-characteristic of most demersal fish

Hoplosternum littorale feeding in a tank.

Life History Breeds seasonally Spawn at the beginning of the rainy season In the wild the Cascadura spawns from June to September Floating nest is dome shaped, comprises of dead grass, twigs, green vegetative matter and sometimes even paper in littered areas. Size of nest is 15-50 cm in diameter (Singh, 1978) Nest is supported with bubbles or froth produced by male. Nest size can contain 2,000 to 22,000 adhesive eggs which may be laid by one or more females. Spawn at the beginning of the rainy season in response of the rising flood waters. There is a change in the physio-chemical factors of the environment as temperature changes,dissolved oxygen,ph, dissolved solids, transparency and depth. Maximum Activity begins in July

Male H. littorale building Floating nest

Floating nest of the H. littorale

the Floating nest from Another angle of the H. littorale

Life History cont… Egg mass is attached to the underside of the nest and the froth adds protection from shock and extreme temperatures. Also provides O2. Females chased away by males after spawning The male during the spawning season grows forwardly curved pectoral spines Eggs are golden in color when laid and darken in hue as they develop. Hatching occurs after 3-4 days. Sac fry cling to the nest for 2-3 days afterwards; fall to the bottom of the water column and begin foraging. Spines used for protection of the nest from predators and also repairing the nest. If it is damaged and removes dead eggs from the mass to prevent fungal infection. Sac fry cling to the nest for 2-3 days in which the yolk sac is absorbed.

Pectoral Spines of the male H. littorale The males are aggressive and when they are going to attack, they approach slowly while hovering in mid water, during the approach the dorsal and pectoral spines are erect and propels itself with the caudal fin or tail. When it near to the target, there is rapid propulsion and sharp lateral turn. Contact is abrupt and abrasions can occur as the rough outer surface of the spine is dragged on the victim.

Life History cont… The male breaks up the nest and distributes the larvae by doing so The fry feed on periphyton Sexual maturity within a year but this is size dependent pe·riph·y·ton- the community of tiny organisms, as protozoans, hydras, insect larvae, and snails, that lives on the surfaces of rooted aquatic plants. Fialmentous algae, minute eggs of some invertebrates, cladocerans, desmids, copepods and rotifers.

Life cycle of the H. littorale

Eggs of the H. littorale

Newly hatched H. littorale

H. littorale at Seven days old

Four week old H. littorale

Lifespan, Dimorphism and General Behavior In the wild the Cascadura can live to 4 years Males grow to 19 cm and females are smaller measuring 16 cm. (Singh, 1978) They feed on detritus and Copepods as well Cascadura are demersal and use barbels which are sensitive to forage for food The animals also show some schooling behaviour Copepods are fresh water crustacean.

References Winemiller, Kirk O. 1986. “Feeding and Reproductive Biology of the Currito, Hoplosternum littorale, in the Venezuelan llanos with comments on the possible function of the Enlarged Male Pectoral Spines.” Environmental Biology of Fishes Vol. 20, No.3, pp. 19- 227. Date Accessed: 15/02/12. http://wfsc.tamu.edu/winemiller/lab/W-curito-EBF87.pdf Masterson, J. Smithsonian Research Station at Fort Piece. 2007. irlwebmaster@si.edu.http://www.sms.si.edu/irlspec/hoplosternum_littorale.htm. Date Accessed: February 17, 2012. Tropical Fish, 2011. Dizhal.info. http://www.sms.si.edu/irlspec/hoplosternum_littorale.htm Date Accessed: March 4, 2012. Ramnarine, Prof. Indar. N.D. “Cascadu Farming : A Manual for the Culture of Hoplosternum littorale.” in General Paper 7, p1-8.Department of Zoology, University of the West Indies, St, Augustine, Trinidad. Dizhal.info. 2007-2012. Hoplosternum littorale - Clay hoplo, Brown Hoplo. Last Updated on 16/07/2011. http://diszhal.info/english/index.php, http://diszhal.info/english/catfishes/en_Hoplosternum_littorale.php Luquet, P., T. Boujard, P. Planquette, Y. Moreau and G. Hostache. 1989. “The Culture Of Hoplosternum littorale: State of the Art and Perspectives” In Advances in Tropical Aquaculture.http://archimer.ifremer.fr/doc/1989/acte-1491.pdf. Date Accessed : February 19, 2012. PlanetCatfish.com. 1996-2012. Callichthyidae, Hoplosternum littorale. Aquatic Republic Network. Last updated: 15/08/11. Date Accessed : 19/02/12. http://www.planetcatfish.com/catelog/species.php?species_id=394 Garcia, Gary W. 2004. “Intensive Wildlife Production Module IV Unit 19 : Aquatic Species Production” in Intensive Tropical Wildlife [ Non-Domestic ] Production Systems : 9.