Reproductive Biology of Hilsa Shad Tenualosa ilisha (Teleostei: Clupeidae) During Spawning Migration in the Shatt Al Arab River and Southern Al Hammar Marsh, Basra, Iraq

Abstract

Aspects of the reproductive biology of Hilsa shad, Tenualosa ilisha from Shatt al Arab river and Southern Al Hammar Marsh during spawning migration have been investigated from the period of April 2013 to March 2014. A total of 1456 specimens were collected using gillnets and landings. The size range of the specimens collected throughout the migration season was 50-460 mm in Total Length (TL). Males were dominant in the smaller lengths, while females did in the larger lengths. The monthly variation in mean length for both sexes showed two distinct peaks, the first was during February-March and the second during September-November. The overall sex ratio showed that females were dominating (1:1.7). The sex ratio varied both spatially and seasonally. Monthly variations in Gonad Somatic Index (GSI) and Dobriyal index indicated that Hilsa shad had a long spawning season with two distinct peaks in April and November. Macroscopic observations of gonads showed six maturity stages. The spatial occurrence of maturity stages suggested that Hilsa shad spawn in all the stations of Shatt al Arab river. The size at 50% maturity was 210 mm for females and 170 for males. The absolute fecundity ranged from 223750-1477780 eggs for fishes with total length range of 200-450 mm and mean weight range of 246.3-891.7 g. The relative fecundity for the same length and weight group ranged from 900.5-1657.1 egg/g. The relationship between absolute fecundity (A F ) and total length was A F = 0.007×TL 3.129 (R 2 = 0.97, n = 62) and that between A F and body weight (B w ) was, A F = 190×B w1.327 (R 2 = 0.95, n = 62).

Tropical hilsa shad (Tenualosa ilisha): Biology, fishery and management

“…An increasing trend in total catch since 2004 could be the outcome of well‐enforced seasonal ban in fishing hilsa brood and juvenile stocks, though segregation of individual initiative's role in the catch of an anadromous species is difficult. Hilsa is a highly preferred edible fish to millions of people living in the Asia and the Middle East countries due to its taste, flavour and delicate culinary properties (Alam, Mohanty, Hoq, & Thilshed, ; Almukhtar, Jasim, & Mutlak, ; Miah, ; Panhwar & Liu, ). The market demands of high‐quality fish in the Middle East, Europe, North America, Japan and Australia have stimulated the hilsa price in recent years.…”

Aspects of reproductive biology of the lesser spiny eel Macrognathus aculeatus (Bloch, 1786) from river Ganga, Uttar Pradesh, India

“…Reproductive biology is one of the most important biological aspects which is a prerequisite for evaluation of the commercial potentialities of a fish stock and its preservation, conservation and management prospects (Jakobsen et al, 2009;Hliwa et al, 2017;Cardoso et al, 2019). GSI has been used as an indicator of reproductive activity of fish and for determination of the breeding season (Sley et al, 2015;Almukhtar et al, 2016). The condition factor is affected by food availability, environmental conditions, population density, physical factors and the physiology of fish including development of gonad maturity (Parrish and Mallicoate, 1995;Uthayakumar et al, 2013).…”

Environmental Factors and Genetic Diversity as Drivers of Early Gonadal Maturation: A Gonadosomatic Index Based Investigation on Indian Shad, Tenualosa ilisha Population of Bangladesh

“…Though it can be found in almost every river, estuary, and marine environment in the country (Ahmed et al, 2008), the number of small sized Hilsa with matured gonad in natural water bodies are increasing alarmingly (Almukhtar et al, 2016). The reason behind this menacing problem observed in the Hilsa of Bangladesh is still unknown.…”