Thumbnail Image

Theses (PG)

Browse

20211
Reset filters
Subject: Fisheries Resource Management × Author: SUYANI NITIN KANJI × End date: 2021 × Start date: 2020 ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    STUDIES ON BIOLOGICAL ASPECTS AND BODY COMPOSITION OF NON-CONVENTIONAL FISH, RED-TOOTHED TRIGGERFISH ODONUS NIGER (RUPPELL, 1836) ALONG MANGALURU AND MALPE COAST
    (KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR, 2021) SUYANI NITIN KANJI; MRIDULA RAJESH
    The red-toothed triggerfish (Odonus niger Ruppell, 1836) is a demersal reef associated fish of the tropical Indo-Pacific area, found at a depth of 5-40 m. The body is blue, the fins are blue-green with blue edge, mouth is small and prominent, the caudal fin is C-shaped and well-developed dorsal fin spines to protect themselves from predators. The present study was based on the observation of 358 individuals (15.4 to 24.0 cm TL) comprising of 257 males and 101 females. The “r” value indicated that the most highly correlated body parameter in relation to TL was standard length (r = 0.91, p<0.01). Four out of eight morphometric characters were environmentally controlled, indicating a wide range of zoogeographical distribution of the species. ANCOVA showed no significant difference (p>0.05) between sexes, therefore, a common equation of LWRs was derived as: W = 0.04705 L2.56089. The Kn indicated almost identical condition for both the sexes. Analysis of gut contents specify that the fish is truly an omnivore and the diet was composed of crustacean remains (51.50%), zooplankton (19.97%), algae (17.70%), squid remains (4.93%), fish remains (3.70%), partially digested matter (2.16%) and detritus (0.24%). The overall sex-ratio of M:F was 1:0.39. Maturity stages indicated that the species spawns for a prolonged period, extending from November to March. Lm50 revealed that the males mature earlier than females. Absolute fecundity ranged from 16,464 to 1,01,962 eggs with an average of 49,467 ± 21675 eggs/female. Ova diameter ranged from 0.01 to 0.28 mm. The HSI values exceeded the GSI in all the months. The muscle composition revealed that the fish has high protein and low fat content and hence regarded as lean fish. Ash content of the species indicated high content of minerals. The present study revealed that O. niger could be a potential source of ω3 fatty acids as well as essential amino acids and micro nutrients such as potassium, phosphorus, sodium, magnesium and calcium.