Age, growth and reproduction of the black scorpionfish,Scorpaena porcus(Pisces, Scorpaenidae), on the Black Sea coast of Turkey

Abstract

SummaryAge, growth and reproduction of the black scorpionfish, Scorpaena porcus were studied in specimens from the coast of the Sinop Peninsula (Black Sea) between March 2002 and April 2003 in order to characterize these population parameters in comparison to specimens from populations of nearby regions. A total of 1086 specimens was captured by beam trawl at the depths between 0 and 30 m. The total number of females (510) was significantly higher than that of males (373). Total length of males and females ranged between 5.7 and 23.6 cm, and 4.9 and 31.7 cm, respectively. The length-weight relationship showed a positive allometric growth. Females grew faster and reached a larger size at age than males (L ¥ = 111.9 cm, K = 0.035 year , u¢ = 2.49 for males). The age range estimated was up to 8 years for females and 5 years for males. Reproduction likely occurs between June and September. Sex ratio varied greatly with season, perhaps indicating different seasonal migratory patterns in adults of different sex. An inverse correlation between gonadosomatic index (GSI) and hepatosomatic index (HSI) was evident during the reproduction seasons. The mean size at first sexual maturity was 17.5 cm TL for females, and 16.7 cm TL for males.

Life-history traits of the southern hemisphere eastern red scorpionfish, Scorpaena cardinalis (Scorpaenidae: Scorpaeninae)

“…The finding that males of S. cardinalis grow significantly faster in terms of length and attain greater sizes than do females is in contrast to the results for other similar-sized species within the genus. It is reported by Bilgin and Ç elik (2009) and Love et al (1987) that females grow larger, more quickly and have longer life spans than do males for S. porcus and S. guttata, respectively. In contrast, La Mesa et al (2005) reported that females of the much smaller species S. maderensis attain smaller maximum sizes than do males.…”

“…In S. porcus and S. guttata, where females grow larger than males, both sexes have similar GSI values (Bilgin and Ç elik 2009;Love et al 1987). S. guttata is known to form large spawning aggregations offshore (Love et al 1987) where it may be advantageous to produce large quantities of sperm.…”

“…It is not known whether this pattern is an artefact of our sampling protocol or whether it reflects a short period when spawning actually occurs. Published monthly GSI values in other Scorpaena congenerics (S. notata, S. guttata and S. porcus) indicate spawning periods of approximately 4 months during which mean GSI values range between ,3 and 5% (Love et al 1987;Muñoz et al 2005;Bilgin and Ç elik 2009). The peak mean GSI values for female S. cardinalis of 2.8% during March 2005 and 4.0% during March 2009 were similar to those reported for other spawning female Scorpaena congenerics; however, the relatively low mean GSI values ( 1%) that occurred for all other months do suggest that spawning may be restricted to a shorter period in S. cardinalis.…”

“…Those species that have been studied tend to be those that grow large and are important components of fisheries (e.g. S. maderensis (La Mesa et al 2005), S. guttata (Love et al 1987), S. scrofa (Ordines et al 2005), S. notata (Whitehead et al 1986), S. porcus (Bilgin and Ç elik 2009), S. elongata (Ragonese et al 2003)). …”

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“…22, 10.86, 11.50, 12.77 and 14.05 cm for S. solea, respectively. Considering the other species caught by the trammel nets, the proportion of scorpion fish under the size at first maturation (17.5 cm TL) (Bilgin and Çelik, 2009) is between 86.9% and 95.4% and for sole, the proportion under the size at first maturation (15.2 cm TL) (Türkmen, 2003) varies between 57.9% and 76.6%. In this study, a large proportion of non-target caught species were under the size at first maturation or minimum allowable catch size.…”