Ekološka i toksikološka istraživanja crnomorske haringe (Alosa immaculata Bennett, 1835) u Dunavu u Srbiji

Abstract

Crnomorska haringa (Alosa immaculata, Bennett 1835) je anadromna vrsta koja veći deo života provodi u jako zagađenom severoistočnom delu Crnog mora, a radi mresta migrira u Dunav. Populacije crnomorske haringe imaju opadajući trend brojnosti, tako da se prema IUCN Crvenoj listi ugroženih vrsta tretira kao ranjiva vrsta (VU). Njen migratorni put radi mresta skraćen je izgardnjom brane Đerdap II do 863 rkm Dunava. Iako je komercijalno značajna, istraživanja na crnomorskoj haringi sprovode se povremeno.Za izradu ovog rada, migranti crnomorske haringe prikupljeni su tokom aprila i maja 2004., 2006., 2007. i 2008. godine na 863 rkm Dunava, neposredno ispod brane Đerdap II.Struktura populacije u odnosu na dužinske klase i dužinsko-težinski odnosi analizirani su na osnovu merenja totalne dužine (TL) i ukupne težine tela (W) jedinki koje su sakupljene u 2004. i 2006. godini. Opseg variranja totalnih dužina tela ulovljenih jedinki iznosio je od 24,2 do 38,7 cm, sa dominacijom klase od 32-32,5 cm. Dobijeni faktori alometrije dužinsko-težinskog odnosa manji su od tri (b<3) za oba pola i za obe sezone uzoraka.Ova studija je imala za cilj da obezbedi i prve podatke o geometrijsko-morfometrijskim karakterima crnomorske haringe, vrednostima gonadosomatskog (GSI) i hepatosomatskog indeksa (HSI) kao i Fultonovog faktora kondicije (K) u Dunavu u Srbiji. Zabeležena je statistički značajna razlika između GSI, HSI i K između oba pola i u obe sezone uzorkovanja. Razlike nisu pronađene samo za vrednosti K između mužjaka i ženki u 2004. godini i za vrednosti GSI i K između ženki uzorkovanih u 2004. i 2006. godini...

The Pontic shad (Alosa immaculata Bennett 1835) is an anadromous species that spends most of its life cycle in the heavily polluted northwestern part of the Black Sea and migrates into the Danube River to spawn. Populations of the Pontic shad have a declining trend, and according to the IUCN Red List of Threatened Species the species is classified as vulnerable (VU). Although its migratory way upstream the Danube is shortened to 863 rkm after the construction of the Iron Gate II dam and even though it represents a commercially important fish species in the lower section of the Danube, the research on the Pontic shad was performed only sporadically in this area.For the purpose of this study, Pontic shad migrants were collected during April and May 2004, 2006, 2007, and 2008, immediately downstream from the Iron Gate II dam.The length frequency distribution and length-weight relationship were determined according to the measured total body length (TL) and body weight (W) of individuals sampled in 2004 and 2006. The length-weight allometric factor (b) was lower than 3 (b<3) for both sexes and both sampling seasons. The length frequency ranged from 24.2 to 38.7 cm, with the domination of the length class of 32-32.5 cm.This study was also aimed at providing the very first data on geometric morphometrics, gonadosomatic index (GSI), hepatosomatic index (HSI), and Fulton's condition factor (K) of Pontic shad migrants from the Danube in Serbia. There were statistical differences in GSI, HSI, and K between males and females in both sampling seasons, except for K between males and females in 2004, and for GSI and K between females in 2004 and 2006...