Studies on the biology and aquaculture potential of feral catfishHeterobranchus bidorsalis(Geoffroy St. Hilaire 1809) (Clariidae)

Abstract

Haematological profile of Heterobranchus bidorsalis (Geoffroy St. Hilaire 1809) was determined. Haematocrit values, haemoglobin concentrations, erythrocyte and leucocyte counts, mean cell haemoglobin concentration, sodium and potassium ions concentrations were 24.75±1.23%, 5.43±0.25 g/100 ml, 1.99±0.52 10"/mm 3 and 7.25±0.60 10 4 /mm 3 , 22.11±0.77%, 802.52±36.97 and 83.54±5.05 mgfl, respectively.H. bidorsalis fingerlings were subjected to a range of salinities, 0, 3, 6, 9, 12 and 15 ppt. The optimum salinity range for survival and good growth performance was determined as 0-3 ppt. Survival was > 85% from 0-9 ppt with no significant differences (P> 0.05), but decreased progressively as salinity increased.Qualitative and quantitative assays of digestive enzymes in the different regions of H. bidorsalis guts revealed an array of carbohydrases, proteases and lipases. Enzyme activity was restricted to the stomach, duodenum and ileum with fewer enzymes recorded in the stomach. The pattern of distribution and relative activity of enzymes correlated with its euryphagous diet.Parasitological examinations conducted on the skin and internal organs of H. bidorsalis yielded a variety of parasites which included three protozoans, two monogeans, six digeneans, four cestodes, two nematodes, two annelids and four copepods. No acanthocephalan infection was detected. Protocephalus sp. (Cestoda) and Allocreadium sp. (Trematoda) had the highest prevalence (>81%) followed by digenean metacercaria (35%).The implications of these results in relation to the aquaculture potential of this catfish is discussed.

Haematological characteristics of clarias gariepinus (Burchell 1822) juveniles exposed to derri elliptica root powder

“…The blood parameters observed were similar to those reported for H. bidorsalis [25]. The direct proportion between the value of PCV, ESR and Hb of C. gariepinus showed that the increase in PCV increased the Hb concentration in the blood of the fish.…”

“…Erythrocyte Sedimentation Rate decreased with increasing D. elliptica concentrations and has been used to ascertain the response of fish blood to stress, pollution, diseases, starvation and nutritional deficiency [24]. Mean corpuscular haemoglobin concentration (MCHC) values reported for Oreochromis niloticus, Heterobranchus bidorsalis and other African fishes were comparable to those of C. gariepinus [25].…”

Haematological profile, food composition and digestive enzyme assay in the gut of the African bony-tongue fish,Heterotis (Clupisudis) niloticus(Cuvier 1829) (Osteoglossidae)

“…No information is available on the quantitative and qualitative assays of digestive enzyme in the gut of H. niloticus, in contrast to other African freshwater fishes whose digestive enzymes assays have been established (OLATUNDE & OGUNBIYI 1976, AKINTUNDE 1985, UYS & HECHT 1987, OLATUNDE et al 1988, FAGBENRO 1990, FAGBENRO et al 1993. In this paper, the occurrence, distribution and relative activities of glycosidases, proteases and lipases in the different gut regions (oesophagus, stomach, pyloric caeca, ileum, rectum) of H. niloticus are described for the first time.…”

Prevalence and Intensity of Helminth Parasites of African Catfish <i>Clarias gariepinus</i> in Lake Manzala, Egypt

“…This African catfish is widely distributed throughout Africa, inhabiting tropical swamps, lakes and rivers, some of which are subjected to seasonal drying [1]. However, farmers are constraint with massive fry and fingerling mortalities, especially in culture system due to the invasion of parasites [7] [8].…”