بررسي وضعيت جنسيتي تاس ماهيان نابالغ صيد شده از آبهاي ايراني حوضه جنوني درياي خزر طي سالهاي 1383-1384

Investigation on sexual status of immature sturgeon captured from the south area of the Iranian waters Caspian Sea during 2004 - 2005

اين پژوهش به بررسي جنسيت و مراحل رسيدگي جنسي، گناد تاس ماهياني كه به روش ترال طي سال هاي1383 و1384 از آبهاي ايراني حوضه جنوبي درياي خزر صيد شده بودند پرداخته است. پس از زيست سنجي ماهيان، قطعه كوچكي از گناد آنها در محلول بوئن تثبيت شد و سپس به آزمايشگاه بافت شناسي انتقال يافت، بافت ها براساس روش هاي معمول بافت شناسي عمل آوري و اسلايدهاي بافتي تهيه و با ميكروسكوپ نوري مورد مطالعه قرار گرفتند. از 253 عدد تاسماهي نمونه برداري شده بترتيب 164 عدد تاسماهي ايراني با متوسط وزن 1210 گرم كه 104 عدد ( 63/4 درصد) ماده و 60 عدد (36/6 درصد) نر بودند. 77 عدد ازون برون با متوسط وزن 1303/3 گرم كه 41 عدد (53/2 درصد) ماده و 36 عدد (8/46 درصد) نر بودند. 3 عدد تاس ماهي شيپ از آنها با متوسط وزن 139گرم كه 1 عدد (33/3 درصد) ماده و 2 عدد (66/7 درصد) نر بودند، 3 عدد تاس ماهي روسي با متوسط وزن 126 گرم كه همگي ماده بودند و 6 عدد فيل ماهي با متوسط وزن 4116/6 گرم كه 4 عدد (66/7 درصد) ماده و 2 عدد (33/3 درصد) نر بودند. كل تاس ماهيان از لحاظ جنسيت 153 عدد (60/5 درصد) از آنها ماده و 100 عدد (39/5 درصد) از آنها نر بودند. كه از لحاظ مراحل رسيدگي جنسي 114 عدد (45/1درصد) در مرحله I، 45 عدد (17/8درصد) در مرحلهI-II، 77 عدد (30/4 درصد) در مرحله II، 11 عدد (4/3 درصد) در مرحله II-III و 6 عدد (2/4درصد) در مرحله III رسيدگي جنسي قرار داشتند. مطالعات حاصل از بررسي بافت شناسي غدد جنسي نشان داد كه تاس ماهيان جوان بوده، در مراحل پايين (بيشتر در مرحله I و II) رسيدگي جنسي قرار داشتند.

In this research, sex and sexual maturation stages of gonads in 253 sturgeon including 164 Acipenser persicus with mean weight 1210gr, 77 Acipenser stellatus with mean weight 1303.3gr, 3 Acipenser nudiventris with mean weight 139gr, 3 Acipenser gueldenstaedtii with mean weight 126gr and 6 Huso huso with mean weight 4116.6 gr that captured by using trawl from the south area of the Iranian coastal part of the Caspian Sea (from the Astara port in the Guilan province to the Turkman port in the Golestan province) during 2004- 2005 were studied. After biometry of fish, gonad samples were taken by biopsy and fixed in Buin,s solution. Gonads were studied histologically based on common methods and studied by using light microscope. Sexually, the results showed in Acipenser persicus, 104 (63.4 %) were females and 60 (36.6%) were males, in Acipenser stellatus 41 (53.2 %) were females and 36 (46.8%) were males, in Huso huso 66.7 % female and 33.3 % male, in Acipenser nudiventris 1 (33.3%) was female and 2 (66.7 %) were males, each 3 Acipenser gueldenestaedtii were females and in Huso huso 4 (66.7%) were females and 2 (33.3 %) were males. Totally, 153 (60.5 %) was female and 100 (39.5 %) was males. Also, 114 (45.1 %) were at stage I, 45 (17.8 %) were at stage I- II, 77 (30.4 %) were at stage II, 11 (4.3 %) were at II – III and 6 (2.4 %) were at stage III of sexual maturity. Histological study of gonads showed that sturgeon populations at the south area of the Caspian Sea are juvenile, because they were at lower stages (I and II) of their sexual maturation.