Choline-exposed Indian major carps and air-breathing fishes reflect successful maturation of gonads reared in a semi-intensive pisciculture system: A histotechnological and ultrastructural introspection

Title : Choline-exposed Indian major carps and air-breathing fishes reflect successful maturation of gonads reared in a semi-intensive pisciculture system: A histotechnological and ultrastructural introspection

Abstract:

The surveillance under direct field-pond application of choline chloride with farm-made-aqua-feed under semi-intensive culture system was undergone to investigate the gonadal maturity in two Indian Major Carps, Catla catla, Labeo rohita and in two air-breathing teleosts, Clarias batrachus, Anabas testudineus reared in a ratio of 2:5:1:1 for a period of 90-d both during dry [November to January: control-dry (CD) and treatment-dry (TD)] and breeding seasons [June to August: control-breeding (CB) and treatment-breeding (TB)]. Results were compared with control [C: pond (C) fed only with farm-made-aqua-feed] and treatment [T: ponds (P1 and P2) fed with farm-made-aqua-feed plus choline chloride @ 350 g bigha-1 fortnightly]. The histotechnological observations of ovary of CD and CB fishes depicted follicular layer separation, follicular atresia, resulting into non-fertile oocytes, and ovarian tissue necrosis; while the TD and TB fishes showed ripe and developed oocytes. Besides, the TB fishes showed improved seminiferous tubules of testis, increased sertoli cells. Ultrastructurally, ovary of CD and CB fishes depicted thick thecal wall of cortical alveolus oocytes (CA), abundance of immature oocytes, single-layered squamous follicular epithelium; whereas, TD and TB fishes displayed well-compacted, well-articulated CA oocytes, mature follicle, and abundance of mucopolysaccharides (MPS) over the oocyte’s surface. Testes of CD & CB fishes depicted less potent primary spermatocytes and weak secondary spermatocytes; whereas, TD & TB fishes showed well-structured spermatogonia, several well-organized secondary spermatocytes, spermatids, and strong motile healthy sperms (SPM). Finally, choline can trigger successful ovarian maturation depicting better yield, which may cause substantial profit to fish farmers.

Biography:

Dr. Subhas Das is a fisheries professional and working in the Department of Fisheries, Government of West Bengal since last almost seventeen years. He has acquired Bachelor of Fishery Science (B.F.Sc.) from the West Bengal University of Animal and Fishery Sciences, West Bengal, India;  M.Sc. in Environmental Science from Vidyasagar University, West Bengal, and  Ph.D. in Environmental Science from the University of Burdwan, West Bengal. Presently he is a registered candidate of  Doctor of Science under the Department of Environmental Science, the University of Burdwan, West Bengal, India. His field of specialization under the broad subject area is Fisheries, Aquaculture, Environment and Ecology, while his major research interest under the thrust area is fish nutrition, fish immunology, eco-toxicology, biochemistry, histology, histochemistry, scanning-electron microscopy, immune-histochemistry, enzyme-histochemistry, haematology, metagenomics, amino acid profiling.