Embryonic development of the endangered Caspian brown trout,Salmo trutta caspius(Kessler, 1877)

Abstract

Summary The Caspian brown trout, Salmo trutta caspius is an endangered species of economic value and better knowledge of its biology will contribute to conservation measures. In the present study we characterized its early development to identify critical embryonic stages, by observing embryos and larvae from a broodstock maintained in captivity incubated at 9 ± 1°C. Morphological analysis of landmark stages of embryonic development revealed that first cleavage occurred at 189 degree‐h, a many‐celled blastoderm formed at 62 degree‐days (dd), a germ ring at 72 dd, the neural keel stage at 88 dd, the blastopore closed at 137 dd, the eye became pigmented at 188 dd and the larvae hatched at 373 dd. The detailed timing of these landmark features will help development of strategies aiming at increased aquaculture production of this species.

Early embryonic development of the vulnerable Shalyni barb,Pethia shalynius(Yazdani & Talukdar, 1975)

“…Studies on embryonic development have great significance as they aid towards the conservation and management of fish species by estimating the fertilization efficiencies, possible restocking of threatened fish species and production of juveniles via successful establishment of aquaculture, understanding a species' habitat requirements, and/or karyological studies to detect any chance events like polyploidy (Najafpour et al., 2019; Weber & Hostuttler, 2012). Previous studies on Pethia (=Puntius) shalynius had primarily focused on the condition factor, morphometry, reproductive cycle, ultrastructure and diet preferences (e.g., Manorama, 2016; Manorama & Ramanujam, 2014, 2017a, 2017b, 2017c).…”

Comparative ontogeny of the digestive tract ofOncorhynchus mykiss♀ xSalmo trutta caspius♂ triploid hybrids to their parental species

“…Caspian brown trout, CBT, Salmo trutta caspius is one of the native cold water species with high potential for aquaculture in the Caspian basin countries (Najafpour et al., 2019). The fish belongs to Salmo trutta and has a greater size, weight and growth rate than other subspecies of the brown trout (Sedgwick, 1995).…”

“…Caspian basin countries (Najafpour et al, 2019). The fish belongs to Salmo trutta and has a greater size, weight and growth rate than other subspecies of the brown trout (Sedgwick, 1995).…”