Acta Adriatica, Vol. 61 No. 1, 2020.
Original scientific paper
https://doi.org/10.32582/aa.61.1.3
Population dynamics of the Mediterranean green crab Carcinus aestuarii Nardo, 1847 (Crustacea: Portunidae)in the Gediz Delta (İzmir Bay, Eastern Aegean Sea)
Eyüp Mümtaz Tiraşin
orcid.org/0000-0003-2597-9609
; Institute of Marine Sciences and Technology, Dokuz Eylül University,Inciralti, Balcova 35340, İzmir, Turkey
Alp Salman
; Faculty of Fisheries, Ege University, Bornova 35100, İzmir, Turkey
Meryem Akalin
; Faculty of Fisheries, Ege University, Bornova 35100, İzmir, Turkey
Okan Özaydin
; Faculty of Fisheries, Ege University, Bornova 35100, İzmir, Turkey
Abstract
A total of 6265 Mediterranean green crabs Carcinus aestuarii were sampled from the Gediz Delta in the eastern Aegean Sea (Turkey) during 24 sampling surveys with a 15-day interval from November 2014 to October 2015. The overall ratio of males to females was 1.8:1. Males were predominant in all sampling surveys, except in September 2015. The ranges of total weight (W) and carapace width (CW) for all crabs were 0.19–45.74 g and 8–53 mm. Male crabs were, on average, larger and heavier than females. The W–CW relationships were \(W=0.0004×CW^{2.88}\) for females, and \(W=0.0003×CW^{2.96}\) for males. The estimated von Bertalanffy growth parameters for females were: CW∞=49 mm, \(K=0.82 year^{-1}\) and \(t_{0} =-0.9 year\), and for males \(CW_{∞} = 54 mm\), \(K=0.92 year^{-1}\) and year. The total mortality rates were 2.25 and 2.27 year-1 for females and \(t_{0} = -0,96\) males, respectively. The breeding season spans from mid fall to early spring peaking in winter. The recruitment of juveniles to the lagoon happens predominantly in summer. The median size at first maturity was 30.6 mm for females and 41.5 mm for males. The average potential fecundity estimate was 63565±36519 oocytes per female crab while the average realized fecundity was 42810±33310 eggs.30,6 mm za žene i 41,5 mm za mužjake. Prosječna potencijalna procjena plodnosti iznosila je 63565 ± 36519 oocita po ženki rakova, dok je prosječna ostvarena plodnost iznosila 42810 ± 33310 jajašaca.
Keywords
Mediterranean green crab; Carcinus aestuarii; growth; mortality; reproduction; size at first maturity
Hrčak ID:
240292
URI
Publication date:
30.6.2020.
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