Publikationsdatum:
2021-07-15
Beschreibung:
Neogobius caspius is an endemic fish species in the Caspian Sea belonging to the family Gobiidae that ecologically play important role as a predator fish in the food chain .The main objective of this research was determination of some reproductive properties of N. caspius in the southwest coasts of the Caspian Sea. Sampling was carried out with a bottom trawler in three stations (Astara, Anzali and Chabuksar) from October 2004 until September 2005. The species was identified based on meristic parameters. The maximum gonadosomatic index (GSI) was recorded at 7.52% for male and 100.12% for female fish in June. A sharp decrease in GSI value from June to the end of September in both sexes was observed and we found that the spawning of the species takes place several times each year. Hence, the species is considered a late spawner. Female to male sex ratio was 1.47:1. Absolute fecundity was in the range 212-1234 eggs and the relative fecundity fluctuated between 18.73 and 29.89 eggs per each gram of the body weight. The correlation between absolute and relative fecundity with age was positive and with total length and full weight was negative. Egg diameter was in the range 0.06 to 0.23mm. The correlation between egg diameter, age and total length was positive.
Schlagwort(e):
Biology
;
Biological surveys
;
Sex ratio
;
Males
;
Gonadosomatic index
;
Fecundity
;
Fish physiology
;
Reproductive cycle
;
Body size
;
Reproduction
;
Females
;
Food chains
;
Endemic species
;
Brackishwater fish
;
Neogobius
;
Gobiidae
;
Neogobius caspius
;
Brackish
;
Caspian Sea
;
Caspian Sea Eurasia
;
Iran
Repository-Name:
AquaDocs
Materialart:
article
,
TRUE
Format:
application/pdf
Format:
application/pdf
Format:
87-98
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