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International Journal of Aquaculture, 2015, Vol.5, No.1, 1
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5
http://ija.biopublisher.ca
1
Research Report Open Access
Biological Characteristics of Pontic Shad (
Alosa immaculata
Bennet 1835) from
the Bulgarian Sector of Danube River
Desislava Rozdina , Galerida Raikova-Petrova, Petya Mirtcheva, Stanislava Velikova
Sofia Univers ity “St. Kliment Ohridski”, Faculty of Biology, Department of General and Applied Hydrobiology, 1164 Sofia, 8 Dr agan Tsankov Blvd., Bulgaria.
Corresponding author Email: d_rozdina@abv.bg
International Journal of Aquaculture, 2015, Vol.5, No.1 doi: 10.5376/ija.2015.05.0001
Received: 28 Sep, 2014
Accepted: 28 Oct, 2014
Published: 05 Jan., 2015
Copyright © 2015
Rozdina et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Rozdina et al., 2015, Biological Characteristics of Pontic Shad (
Alosa immaculata
Bennet 1835) from the Bulgarian Sector of Danube River, International
Journal of Aquaculture, Vol.5, No.1: 1-5 (doi: 10.5376/ija.2015.05.0001)
Abstract
The annual fluctuations in the average length of the catches of
A. immaculata
, from the Bulgarian sector of the Danube
River were studied. Between the years of 1962 and 2010 the average length varies within 23.7 cm and 26.3 cm, while in 2011, there
was a significant drop in the average fish length (20.1 cm). The fecundity of the Pontic shad declines with increasing the linear and
weight temp of growth. The condition factor was calculated by the coefficient of Fulton (K
f
) using the total and gutted weight. The
value of K
f
, calculated using the gutted weight of the individuals is 1. For males and females, the values of K
f
are respectively 1.05
and 1.07. Condition factor was also studied for each age group separately, for males and females and combined for both sexes.
Keywords
Alosa immaculata
; Length-age relationship; Fecundity; Condition factor; Danube river
1 Introduction
The Pontic shad (
Alosa immaculata
Bennet 1835) is
the largest species of the family Clupeidae in the
Black Sea. It is an anadromous fish species which
inhabits Black and Azov Sea, and for spawning enters
the big rivers. In Danube River for spawning migrates
the individuals inhabiting the western part of Black
sea (Kolarov, 1958a, Navodaru, 2001).
The Pontic shad is an economically important fish. In
the period 2003–2011, the annual catch of Pontic shad
in the Black Sea and the Danube has dropped
averagely with 3.5 times (Ministry of Agriculture and
Food). Despite it is a commercial fish species
A.
immaculatа
is vulnerable according to IUCN and
Bulgarian Red Book (http://www.iucnredlist.org/apps/
redlist/details/907/0; http://e-ecodb.bas.bg/rdb/bg/vol2/
Alpontic.html). The species is also included in Annex
2 and 4 of the Bulgarian Biodiversity Act and Annex 2
of the Habitats Directive 92/43ЕЕС for 15 Protected
areas from the national Natura 2000 ecological net.
The sustainable exploitation of this commercial fish
species requires detailed study of the biological
parameters of its populations. There is an insufficiency
of contemporary data about the biology of Pontic shad
in Danube River. Data about the species in Bulgarian
water area were published by Drenski (1923; 1931;
1951; 1958), Kolarov (1958 а, б; 1960 а, б; 1962;
1964; 1965; 1978; 1979; 1980; 1982; 1983; 1991),
Prodanov and Kolarov (1983), Stoianov et al. (1963),
Marinov (1966), Karapetkova and Penchev (1973),
Karapetkova (1974; 1975; 1976), Pehlivanov (1999),
Sivkov (2000; 2003), Karapetkova et al. (2003),
Trichkova et al. (2006), Shlyakhov and Daskalov
(2009), Raikova-Petrova et al. (2013) and Rozdina et
al. (2013).
The aim of this article is to study the relation between
the basic biological parameters in
A. immaculata
from
the Bulgarian sector of Danube River.
2 Material and methods
Altogether 293 specimens of
A. immaculata
were
collected in April and May 2010 and 2011 during the
spawning migration of the species in Danube River.
Sampling points were located in the area between the
towns Lom and Vidin, with geographical coordinates
as follows: Sampling point 1: 43°54'17.96"N and
22°50'27.45"E; Sampling point 2: 43°47'40.46"N and
23°4'50.41"E; Sampling point 3: 43°50'45.61"N and
23°18'44.17"E. Gill nets were used which mesh size
from 32 to 88 mm and a length of 50 m.
Each specimen was measured the standard length (L)