Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2020Scopus SJRQ3Age and growth of the lessepsian migrant lagocephalus spadiceus (Actinopterygii: Tetraodontiformes: Tetraodontidae) from the gulf of iskenderun, north-eastern mediterranean, turkey
Başusta, Asiye; Başusta, Nuri; Ozcan, Ebru Ifakat; Girgin, Hülya
Background. The population of Lagocephalus spadiceus (Richardson, 1845), one of the Lessepsian species that migrated from the Red Sea to the Mediterranean Sea through the Suez Canal, has been growing rapidly in Turkey in recent years. This situation poses a serious danger to fisheries and human health. There is little information about the biology of this species. The presently reported study permits a greater understanding of the age and growth characteristics of the pufferfish L. spadiceus from the Gulf of Iskenderun, north-eastern Mediterranean. Materials and methods. Samples were captured by commercial bottom trawlers at depths of 24–50 m during 9 trawling operations conducted during the fishing seasons between 2012 and 2013 in the Gulf of Iskenderun, northeastern Mediterranean. Age determinations were carried out using vertebrae. Images of vertebrae suitable for age determination were obtained with a dissecting microscope. The index of the mean percentage error (IMPE) was calculated to assess the precision of the age determinations between two independent readers. Growth parameters for all individuals were then determined by fitting observed and length-at-age data using the von Bertalanffy growth equation. In addition, the condition factor (CF) was determined. Results. A total of 1116 specimens (529 females and 587 males) were sampled, ranging from 6.7 to 34.0 cm in total length and from 4.30 to 557.64 g in weight. The female-to-male ratio was 1:1.1. Age determination was conducted using vertebral band counts. The age of the examined specimens ranged from 0 to 10 years. One female individual was determined to be 17 years of age (45.6 cm and 1269.0 g). The von Bertalanffy growth equations were Lt = 47.21[1 – e–0.116(t+ 2.04)] and Wt = 1296.18 [1 – e–0.116(t+ 2.04)]2.846 for females, Lt = 46.36 [1 – e–0.133(t+ 1.76)] and Wt = 1381.86 [1 – e–0.133(t+ 1.76)]2.817 for males and Lt = 46.90 [1 – e–0.120(t+ 1.97)] and Wt = 1345.67 [1 – e–0.120(t+ 1.97)]2.831 for all individuals. The growth performance index (Ф´) value was calculated as 2.421 for all individuals. The condition factor ranged from 0.890 to 2.768 for females and from 0.899 to 2.767 for males. Conclusions. It is very important to investigate L. spadiceus, an invasive species, in order to prevent its harmful effects on fisheries and human health. As this study is the first study on the age and growth of L. spadiceus in the northeastern Mediterranean, it will significantly contribute to future ecosystem conservation and management strategies.
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İncele - MakaleAçık Erişim2020Scopus SJRQ3Age and growth of the phaeton dragonet, Synchiropus phaeton (Actinopterygii: Perciformes: Callionymidae), from the gulf of iskenderun, north-eastern mediterranean, Turkey
Başusta, Asiye; Ozcan, Ebru İfakat; Başusta, Nuri
Background. Synchiropus phaeton (Günther, 1861) is a sexually dimorphic, benthic species that inhabits mud bottoms. This fish is one of the important by catch species in the trawl fishing. There is no commercial value. But it has ecological importance in this area. The information about the biology of S. phaeton is very limited. This study was conducted to investigate the age and growth relation of phaeton dragonet inhabiting the Gulf of Iskenderun, north-eastern Mediterranean coast of Turkey. Materials and methods. A total of 289 phaeton dragonets were collected as discards during the commercial trawl fishing at the depth range of 100–150 m in the Gulf of Iskenderun, north-eastern Mediterranean. The fish age was determined from sagittal otoliths. The age readings were performed using Leica S8APO microscope and were documented with the Leica Application Suite (Ver. 4.8.0) software. The index of the mean percentage error (IMPE) was calculated to assess the precision of the age determination between two independent readers. Growth parameters for all specimens were subsequently determined by fitting the observed and the length-at-age data using the von Bertalanffy growth equations. Total length–weight relations (LWRs) and the condition factor (CF) were determined. Results. The total length and weight of S. phaeton ranged from 7.0 to 19.0 cm and from 2.01 to 22.0 g, respectively. The age of the studied individuals ranged from 2 to 7 years. The parameters of von Bertalanffy growth fitted to the mean observed total lengths-at age for each sex separately and were estimated as L∞ = 23.358 cm, K = 0.248 year–1, t0 = –0.501 years for females and L∞ = 26.543 cm, K = 0.156 year–1, t0 = –0.662 years for males, respectively. The overall growth performance index (G) value was determined as 3.46 for the combined sexes. The total length– weight relations were determined as W = 0.0121TL2.55, R² = 0.94; 95% confidence intervals of b = 2.395–2.687, t-test P < 0.05 for females and W = 0.0094TL2.64,R2 = 0.93; 95% confidence intervals of b = 2.470–2.803, t-test P < 0.05 for males. The types of growth were found negatively allometric (b < 3). The highest condition factor was found at the age of 2 (0.62), while the lowest was found at the age of 6 (0.26). Conclusions. The presently reported study provides the first data on the age and growth of the S. phaeton that had not been studied previously in the Gulf of Iskenderun, north-eastern Mediterranean of Turkey. This study will contribute significantly to the conservation and management strategies of the species of S. phaeton in the future.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2018Scopus SJRQ3Anesthetic efficiency of 2-phenoxyethanol on broodstock of salmo munzuricus, a new trout species originating from munzur stream; [Munzur akarsuyu orijinli yeni bir alabalık türü olan salmo munzuricus’un anaç bireyleri üzerinde 2-fenoksietanol’ün anestezik etkinliği]
Can, Erkan; Başusta, Asiye; Karataş, Bilal
Salmo munzuricus is a newly-named species of trout that spreads through rivers flowing along the Munzur Valley National Park. The efficacy of anaesthetic 2-phenoxyethanol was evaluated in indigenous brown trout in the present study. Fish were divided into three weight classes: 100-200 g (W1), 200-400 g (W2) and 400-600 g (W3) and they were exposed to four concentrations of anaesthetic (0.2, 0.3, 0.4 and 0.5 mL L-1). The lowest induction time was identified in the group W3 while the highest one was in the group W1. The lowest recovery time occurred after 73.2±3.83 sec in the group W3 and the highest one was 136±31.46 sec in the group W1. The recovery times were increased with increasing the concentration of 2-phenoxyethanol in the group W1. However, recovery times in the groups W2 and W3 were significantly longer than observed in W1, generally. Besides, it was indicated that fish size affected induction times and recovery times. As a result of the present study, the most appropriate concentrations were determined as 0.4 mL L-1 at weights of 100-400 g while 0.5 mL L-1 at weights of 400-600 g for 2-phenoxyethanol in Salmo munzuricus broodstock.
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