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Length–weight relationships and condition factors of several endemic and native species of the genera Alburnoides, Alburnus and Squalius

Kurtul Irmak, Kaya Cüneyt, Onay Hatice, Bayçelebi Esra, Turan Davut

Oceanological and Hydrobiological Studies

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2024

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Vol. 53, No. 3

227--236

EN

The present study examined for the first time both length–to–weight relationships and condition factors of ten species belonging to three endemically rich genera: Alburnoides (nspecimens = 361), Alburnus (nspecimens = 36), and Squalius (nspecimens = 205). Fish were sampled in several lakes and streams using electroshocking. Fish samples ranged from 3.60 cm to 27.40 cm in total length and from 38.00 g to 250.02 g in total weight. The coefficient of determination for all populations was R2 ≥ 0.95, while the b value varied between 3.0158 and 3.4957 for all sampling locations. The latter ranged from 3.0158 to 3.4957 for Alburnoides, from 3.0357 to 3.2327 for Alburnus, and from 3.0743 to 3.2143 for Squalius populations. Fulton’s condition factor was calculated for all populations. The research presented here focused on data-deficient endemic and native species of Anatolian freshwater resources, and the results obtained may prove useful in biodiversity management strategies.

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An ichthyofaunal amendment with the length-weight relations and condition factors of some endemic and invasive freshwater fishes from Western Anatolia

Kurtul Irmak, Kaya Cüneyt, Şen Arda, Özcan Ceylin, Ercivan Deniz, Demirel Kaan, Güngör Melike, Ilhan Ali, Sarı Hasan Musa

Oceanological and Hydrobiological Studies

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2023

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Vol. 52, No. 4

389 --398

EN

In the scope of this study, fish fauna of Küçük Menderes River and its tributaries, updated with the comparison of the recent ichthyofaunal studies, as well as the length-weight relations (LWR) and condition factors (CF) were estimated for 7 freshwater fish species belonging to six families from the river basin: endemic Oxynoemacheilus eliasi, Cobitis fahireae; invasive, Carassius gibelio, Atherina boyeri, transloce Perca fluviatilis and the native Squalius fellowesii, Cyprinus carpio. The fish samples were collected with various fishnets and DC electro-fishing devices from six stations in 2018 and 2019. The LWR of the fishes was studied based on 379 specimens. The estimated values of parameter b ranged from 2.884 (A. boyeri) to 3.176 (C. fahireae). The coefficient of determination (R2) was changed between 0.792 to 0.980 for all sampling localities. In the study, Fulton’s condition factor ranged between 0.391 (S. fellowesii) to 3.080 (S. fellowesii); the relative condition factor ranged between 0.346 (O. eliasi) to 2.746 (S. fellowesii), respectively. This research is anticipated to contribute valuable insights for the conservation of the species, while also furnishing essential data to inform future fisheries management studies in the region.

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Growth parameters of invasive gibel carp Carassius gibelio (Bloch, 1782) in Lake Marmara (Turkey)

Ilhan Ali, San Hasan M, Kurtul Irmak

Oceanological and Hydrobiological Studies

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2020

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Vol. 49, No. 4

383--390

EN

The objective of this study was to determine growth parameters, such as age–length and length–weight relationships, as well as condition factors and sex ratio, of the Carassius gibelio (Bloch, 1782) population in Lake Marmara (western region of Turkey), which is one of the most important fishing areas. Fish were caught on a monthly basis by gillnets and trammel nets (mesh size 10–50 mm) between March 2012 and February 2013. A total of 1058 specimens (809 females and 249 males) were examined. The female–male ratio was 1:0.31. The maximum age was determined as VI and V for females and males, respectively. The total length of females and males ranged from 10.0 to 27.5 cm and from 10.2 to 24.0 cm, respectively. Their weight varied from 17.1 to 378.4 g and from 17.7 to 244.9 g, respectively. Length–weight relationship parameters were a = 0.014 and b = 3.040 for females and a = 0.015 and b = 3.039 for males. Von Bertalanffy growth parameters of the C. gibelio population were as follows: L∞ = 35.86 cm, k = 0.189 year−1, t0 = −1.238 years. Minimum and maximum condition factors were 1.56 for females in October and 1.82 in May and 1.67 for males in September and 1.94 in January.