Köyceğiz-Dalyan Lagün Ekosistemi Kefal Populasyonlarının Büyüme Performans İndeksleri

As it is common in tropical and temperate zones, mullet species constitute the most important fish species caught along the coast and estuaries of Turkey. In terms of ecology, tourism and and fish productivity (52 kg/ha), Koycegiz-Dalyan Lagoon Ecosystem (KDLES) is the most important lagoon, with a 5500 ha surface area, is the Mediterranean Coast of Turkey. In the dalyan (barrier fish trap) systems; approximately 225 tons (80-405 tons) of mullets are caught to obtain 5 tons of dried fish eggs per year. Seventy percent of fish production in the lagoon is composed of mullets. The mullet samples were collected monthly between October 1992 and September 1994 from eight stations (one of them is a marine station) by trammel nets. The ages were determined using by scales anda ge composition varied form 0 to 6 ages. Species composition of 1159 sampled individuals were proportionally determined as Mugil cephalus 45%, Liza aurata 35%, Liza saliens 14%, Liza ramada 12%, Chelon labrasus 6%. The growth performance indices calculated from von Bertalanffy growth parameters using by all individuals for the M. cephalus, L. aurata, L. saliens, L. ramada and C. labrasus were determined as 2.957, 2.866, 2.692 and 2.719, respectively. The highest growth performance index was calculated for M. cephalus. The growth performance indeces of mullet species in Köyceğiz-Dalyan Lagoon Ecosystem were found around the world averages.

RESEARCH OF PHYSIOLOGICAL AND BIOCHEMICAL PARAMETERS OF GOLDEN MULLET (LIZA AURATA, RISSO) IN THE CASPIAN SEA

The paper outlines the study of the physiological and biochemical parameters of golden mullet (Liza aurata, Risso) in the Caspian Sea. Collecting material was carried out in the western part of the Northern and Middle Caspian in September-October 2019. The female and male species were analyzed. The histomorphological investigation of the gonads of females and males indicated the completion of spawning. The morphological picture of the gonads of golden mullet of both sexes corresponded to the maturity scale of this species as applied to the Caspian region. In the blood there was determined the concentration of hemoglobin, total serum protein, total lipids, triglycerides, cholesterol, glucose, and inorganic phosphorus. A valid positive correlation dependence (p < 0.05) of weight and length of females (r = 0.9340) and males (r = 0.9320) was stated. In females high correlations were recorded between the levels of total serum protein and cholesterol (r = 0.9071), total serum protein and hemoglobin (r = 0.9706), glucose and hemoglobin (r = 0.8897) with a statistical significance level of p < 0.05. The revealed statistical dependencies of physiological and biochemical parameters of fish blood indicated their important role in the body in optimizing the total energy costs after spawning. According to the study of males, there has been found a high (r = 0.9195) significant (p < 0.05) correlation relationship between the content of hemoglobin and cholesterol in the blood. The content of total lipids in muscles, gonads and liver of females and males of golden mullet were comparable. The levels of water-soluble protein in the muscles, liver, and gonads of fish of both sexes did not differ significantly. The obtained research results on the complex of physiological and biochemical parameters of golden mullet will significantly increase the volume of reliable information about the physiological status of the organism of the studied species of mullet in the modern ecological conditions of the Caspian Sea.

Growth of Fry Fish of 4 Species of Family Mugilidae in Experimental Recirculation Water System

The collected in nature fry of Mugil cephalus, Liza aurata, L. ramada and Chelon labrosus that arrive in massive schools at the coastline of Greece were reared in small aquaria (50 L) of a recirculation system from the size of about 3.0 cm TL (50 fish per aquarium), using brackish (15 ppt) water and artificial high protein food. It was found that for a period of 80 days, growth performance was high at 23 oC, reaching values for weight increase between 592 (M. cephalus) and 2281 % (L. aurata). Food Conversion Ratio (FCR) was best (1.04) for L. aurata and worst (2.04) for M. cephalus. All species responded well as exhibited by an increase in their Condition Factor (CF) and mortality was almost absent.

Helminth parasites of fish of the Kazakhstan sector of the Caspian Sea and associated drainage basin

SummaryThe northern section of the Caspian Sea is an important fishery for Kazakhstan. In the present study, a total of 606 individuals of 13 fish species were collected. For each of Abramis brama, Alosa saposchnikowii, Atherina boyeri caspia, Carassius auratus, Clupeonella cultriventris, Cyprinus carpio, Liza aurata, Leuciscus aspius, Rutilus rutilus caspius, Sander lucioperca, Sander marinus, and Sander volgensis 50 individuals were examined whilst 6 individuals of Siluris glanis were examined. The nematode parasite Anisakis schupakovi was found in all fish species except Liza aurata, Carassius aurata, Cyprinus carpio and Rutilus rutilus at intensities ranging from 1 to 1197 parasites per infected fish. Trematodes of family Diplostomidae were also isolated from all fish except Alosa saposhnikowii, Clupeonella cultriventris and Sander marinus at intensities ranging from 1 to 242 parasites per infected fish. Other parasites found included the nematodes Porrocaecum reticulatum, Contracecum sp, Camallanus sp and Eustrongylus excisus; the cestodes Neogryporhynchus cheilancristrotus, Bothriocephalus opsariichthydis; the monogenean parasites Mazocraes alosa, Ancyrocephalus paradocus, Gyrodactylus spp, Ligophorus vanbenedenii and Dactylogyrus spp; and the crustacean parasites Ergasilus sp. and Synergasilus sp. In addition one unidentified species of nematode and a bivalve of the genus Unio was recovered from Rutilus rutilus caspius. There was no association between Fulton’s condition index and intensity of parasite infection.