Olfactory Sensory Neuron Morphotypes in the Featherback Fish, Notopterus notopterus (Osteoglossiformes: Notopteridae).

Background: As in other vertebrates, olfactory sensory neurons (OSNs) in fishes are the main components of sensory part of olfactory epithelium that relay olfactory information (smell and taste) to the brain.

Purpose: Objective of the present study was to analyze if any polymorphism occurs in the OSNs in a featherback fish, Notopterus notopterus as far as the teleost lineage is concerned.

Methods: With the help of neuronal staining technique, polymorphism of OSNs in N.

Cytoarchitectonic study of the brain of a dwarf snakehead, Channa gachua (Ham.). I. The telencephalon.

Cytoarchitectonic pattern of the telencephalon of a dwarf snakehead, Channa gachua, is studied by serial transverse sections of the brain (Kluver and Barrera staining). On the anteriormost extremity of the telencephalon, olfactory bulbs terminate that are sessile. The olfactory bulbs comprise four concentric layers, which from outside toward the center are olfactory nerve layer, a glomerular layer, mitral cell layer, and internal cell layer.

Annual reproductive phase-related profile of sex steroids and their carrier, SHBG, in the Indian major carp, Labeo rohita.

This study reports annual cyclic changes in the plasma levels of sex hormone binding globulin (SHBG), sex steroids (E(2), estradiol; T, testosterone; P, progesterone) and protein (PRT) in correlation with reproductive phases in both sexes of an Indian major carp, Labeo rohita. Plasma SHBG, E(2), T and PRT levels in females and SHBG and T levels in males showed steady increases (p<0.005) in parallel with the gonadosomatic index (GSI) escalation in the preparatory and prespawning phases attaining peak levels before spawning.

[Organization of olfactory system of the Indian major carp Labeo rohita (Ham.): a study using scanning and transmission microscopy].

Catla catla, Labeo rohita, and Cirrhinus mrigala are important alimentary fish in India. Their reproduction (breeding) depends on season. The fish perceive external factors-stimuli and chemical signals through the olfactory system that plays the key role in the central regulation of reproduction.