Population dynamics of deep-water pink shrimp (Parapenaeus longirostris Lucas, 1846) (Decapoda, Penaeidae) in the coastal waters of Tuzla (Eastern part of the Sea of Marmara)

In this study, the population parameters, recruitment period, exploitation rate, and stock status of deepwater pink shrimp (Parapenaeus longirostris Lucas, 1846) in the eastern Sea of Marmara were investigated. Growth showed negative allometry, and, b-values were significantly lower than 3 for females′ and males′ (p < 0.05). Females and males' growth performance indexes (φ) of P. longirostris were determined as 2.91 and 2.89, respectively. Asymptotic carapace lengths (CL∞), growth coefficients (K), and theoretical birth ages (t0) of females and males were calculated as 32.55, 28.67 mm, and 0.760, 0.950, and –0.233, –0769, respectively. The maximum exploitation rates (Emax) were calculated as 0.82 for females and as 0.90 for males. The first capture lengths (CL50) for females and males were estimated to be 18.78 and 18.07 mm, respectively. Two recruitment periods were determined for P. longirostris for females and males. The recruitment period was estimated to be between February and April, July and November. The yield per-recruit (YPR) analysis for females and males revealed that E0.1 = 0.72 and 0.80 approached the maximum exploitation rate (Emax = 0.82 and 0.90), respectively, indicating that exploitation for P. longirostris was in quadrant category "C" in the Eastern Marmara Sea. This status demonstrated active fishing, according to the quadrant rule

Age, Growth and Length-weight Relations of Common Sole (Solea solea Linnaeus, 1758) from Southern Aegean Sea

In this study, age and sex compositions, length distributions, growth parameters and length-weight relationships of common sole populations were determined in Güllük Bay, southern Aegean Sea, Turkey. Trammel nets and beach seines which have different full mesh sizes were used to obtain samples. Sex ratio (female:male) was found to be 1.14:1. Growth parameters of the common sole in Güllük Bay was described as; L∞=33.95, K=0.208 y-1, t0=-0.032, L∞=31.98, K=0.236 y-1, t0=-0.037 y and L∞=29.11, K=0.324 y-1, t0=-0.030 y, for sexes combined, females and males, respectively. Lengthweight relationships for combined sexes, females and males were W=0.0079L3.064, W=0.0072L3.101 and W=0.0088L3.024, respectively. Combined individuals and females showed positive allometric growth and males showed isometric growth. Ages ranged between 0-9 years. Study results could be useful for further common sole fishery management strategies