Length-Weight Relationships of Four Lessepsian Puffer Fish Specıes From Muğla Coasts of Turkey

In this study, length-weight relationships were given belonging to Tetraodontidae family: Lagocephalus sceleratus (Gmelin, 1789), Lagocephalus spadiceus (Richardson, 1845), Lagocephalus suezensis Clark & Gohar, 1953 and Torquigener flavimaculosus Hardy & Randall, 1983. Specimens were collected via different fishing activities (e.g. longline, trammel net, bottomtrawl) from Muğla coasts (South Aegean Sea, Turkey) during 2014. Specimens were thown back sea after length and weight measurements because of restrictive legal requirements. Minimum, maximum and mean total lengths and weights were established as 5.3, 10.6, 7.25 cm, 3.96, 31.57, 11.28 g for T. flavimaculosus, as 16.7, 63.8, 29.34 cm, 64.36, 2968.42, 342.39 g for L. sceleratus, as 11.8, 27.9, 16.48 cm, 27.98, 287.48, 74.24 g for L. spadiceus and as 8.6, 15.9, 10.62 cm, 7.94, 43.56, 15.47 g for L. suezensis, respectively. LWR equations were calculated as follow: W= 0.03761 *L2.8363(R2= 0.896) for T. flavimaculosus, W= 0.01646 *L29272(R2= 0.974) for L. sceleratus, W= 0.03327 *L2.7315(R2= 0.913) for L. spadiceus and W= 0.02138*L2.7586(R2= 0.871) for L. suezensis. Four pufferfish species were show negative allometric growth (A-) model.

In the fisheries science, length-weight relations have a several uses: Estimate weight from length for individual fish and for length classes of fish; estimate standing-crop biomass when the length frequency distribution is known (Anderson & Gutreuter, 1983;Petrakis & Stergiou, 1995); convert growth-in-length equations to growth-in weight for prediction of weight-at-age and use in stock assessment models (Pauly, 1993); calculate condition indices (Anderson & Gutreuter, 1983;Petrakis & Stergiou, 1995); and compare populations from different regions in terms of their life histories and morphology (Petrakis & Stergiou, 1995).
The purpose of the relationships presented here is to enable researchers merely to derive length estimates for the species, found in the Muğla coasts, that are weighed but not measured, or vice versa.

Material and Methods
In this study, length-weight (LWR) relationships were calculated for: L. sceleratus (Gmelin, 1789) (n= 125), L. spadiceus (Richardson, 1845) (n= 117), L. suezensis Clark & Gohar, 1953 (n= 84) and T. flavimaculosus Hardy & Randall, 1983 (n= 28) specimens collected seasonally via different fishing methods (e.g.longline, trammel net, bottom trawl) from Muğla coasts (South Aegean Sea, Turkey) and Each fish was measured for total length (TL) to the nearest 0.1 cm and weighed (wet weight, W) to the nearest 0.01 g on board during the year of 2014, all specimens were thown back sea after length and weight measurements because of restrictive legal requirements.
The length-weight relationships were estimated using the equation W= aLb, where W is total weight (g), L the total length (cm), a the intercept and b the slope.The degree of association between the variables was computed by the determination coefficient, r2.The significance of the regression was assessed by ANOVA, and the b-value for each species was tested by t-test to verify that it was significantly different from the predictions for isometric growth (b= 3) (Pauly, 1993).

Results and Discussion
We were collected 354 fish specimens belonging Tetraodontidae familiy, two genus (Torquigener and Lagocephalus) and four species: 7.90% of T. flavimaculosus, 35.31% of L. sceleratus, 33.05% of L. spadiceus and 23.73% of L. suezensis.Values of the allometric coefficient (b) ranged from 2.7315 for L. spadiceus to 2.9272 for L. sceleratus and all species were shows negative allometric growth (A-) model.

Discussion
Comparisons of length-weight relationships of Torquigener and Lagocephalus species in the Mediterranean were given in Table 3. Concerning all species, the b-values of the relationship ranged from 2.645 to 3.150.Negative allometric growth was observed in all studies while only one study showed positive allometric growth (Wang et al., 2011).Although the findings are compatible, fish samples in the present study were intermittently collected throughout the year.Estimated LWR parameters should be considered only as mean annual values for most of these species since the data were collected over an extensive period of time and are not representative of any particular season (Dulčić & Glamuzina, 2006).Additionally, the estimation of LWR parameters depends on a series of factors, such as seasonality, habitat, sex and maturity of a species (Karachle & Stergiou, 2008).The lenght-weight relationships provided in this study could serve as a useful tool in the future studies in the wider study area and as a future reference for comparisons of similar parameters estimated in other Mediterranean regions for four pufferfish species.It is also essential to monitoring their ecological and socio-economic impacts.

Table 2 .
Length-weight relationships of Torquigener and Lagocephalus species from Muğla coasts (South Aegean Sea, Turkey).Descriptive statistics and sample size (N) of four pufferfish species were given in Table1, collected from Muğla coasts and length-weight relationships, the coefficient of determination (R 2 ), the Standard error (SE) and confidence interval (CI) of b.Of Torquigener and Lagocephalus species from Muğla coasts (South Aegean Sea, Turkey) shown in Table2.