title: Stage-dependent hatching responses of rohu (Labeo rohita) embryos to different concentrations of cryoprotectants and temperatures.
abstract: Hatching performances of three embryonic stages of postfertilization rohu (Labeo rohita) (9-, 12-, and 15-h) were examined after treatment with various concentrations (0.5-4.5M) of two cryoprotectants (methanol and propylene glycol) supplemented with 0.1M trehalose. Different lengths of storage (1-48 h) and temperature (-4 degrees C to ambient) were studied. Of the three stages of embryonic development, the 12-h stage proved to be the most suitable stage for low temperature storage, showing the highest percentage of hatch out (72+/-2%) with 2.0M methanol and 0.1M trehalose. Methanol was more useful for storage at higher temperatures and propylene glycol at subzero temperatures. The maximum possible duration of effective storage of 12-h embryos was 31h in 2.0M methanol at 0 degrees C. No hatch out was found beyond 31h of storage with all concentrations of methanol at 0 degrees C. The results of interactions was that the optimal concentration of methanol was 3.0M at 4 degrees C, 2.0M at 0 degrees C, and 1.5M at 4 degrees C. Among three embryonic stages 12-h stage showed better results in trehalose treatment than sucrose. Among all concentrations of trehalose tested 0.1M gave the maximal survival rate of the rohu embryos.
authors.affiliation: Department of Zoology, University of Kalyani, Kalyani-741 235, Nadia, West Bengal, India.
authors.forename: M M
authors.initials: MM
authors.lastname: Ahammad
authors.forename: D
authors.initials: D
authors.lastname: Bhattacharyya
authors.forename: B B
authors.initials: BB
authors.lastname: Jana
mesh_terms: D000818:Animals; D002347:Carps / Q000196:embryology*; D015925:Cryopreservation / Q000379:methods; D003451:Cryoprotective Agents / Q000494:pharmacology* / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000502:physiology; D005398:Fisheries / Q000379:methods; D000432:Methanol / Q000494:pharmacology* / Q000633:toxicity; D019946:Propylene Glycol / Q000494:pharmacology* / Q000633:toxicity; D013395:Sucrose / Q000494:pharmacology* / Q000633:toxicity; D013696:Temperature; D013997:Time Factors; D014199:Trehalose / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D003451:Cryoprotective Agents; D013395:Sucrose; D019946:Propylene Glycol; D014199:Trehalose; D000432:Methanol