Histological Characteristic of the Gonads of Sardine Sardina Pilchardus (Walb, 1792) in the Coast East of Algeria (Gulf of Annaba)
Assia BEDAIRIA, Abdallah borhane DJEBAR, Marion JARRAYA

To illustrate the different kinetics of oogenesis and spawning strategies, reproduction in the Sardine (Sardina pilchardus, Walbaum 1792) was discussed. The histological samples, realized over the 3 periods of sexual cycle: oogenesis, egg and rest, were analyzed for 2217 specimens caught in the period from November 2015 to October 2016 using a microscopic scale of oocyte development with 6 stages. The histological results allowed us to determine the size of first sexual maturity is 12 cm, acquired during the third year of life of the sardine. Monthly monitoring of the evolution of macroscopic and microscopic stages of sexual maturity, allowed us to suggest that the waters of the coastal eastern Algeria, sardines spawn from December to March. Sexual rest is observed in the 2 sexes in May, during the summer and part of fall. Spawning and sperm emission ending in April. Microscopic observations show six stages of maturity in females and four males. Earlier maturation, oocytes come together in one lot, come into vitellogenesis and evolve synchronously to mature simultaneously. Separated from each other by the gap, they are issued in a fractional short laying. Ongoing recruitment of pre-vitellogenic oocytes determined new ways of oogenesis and lying, there are as many as egg laying lots placed in vitellogenesis. This type of distribution allows multimodal oocyte laying series with lots of small eggs released during a long period of time, postspawn is difficult to identify. These results illustrate the complexity of multiple clutches.

Full Text: PDF     DOI: 10.15640/aijb.v4n2a2