Some biological aspects of Greater lizardfish (Saurida tumbil) caught on the Iranian shore of the Persian Gulf (Bushehr Province) were studied from February 2007 to February 2008, by regular monthly collections to gain a deeper knowledge about this commercial species. A total of 691 specimens, including 39 immature, 114 males and 538 females were collected. The mean of the sex ratio was 1:5 (M: F) which was inverse in juvenile where males were the dominant group. For age determination, scales in all specimens and for comparison, otoliths in some, were used. The total length of fish ranged from 25.5 to 53.5 cm in males and the total weight of fishes ranged from 116 to 1125 g. The curvilinear relationship between the total length and total weight was w=0.0093 L2.9369 for males. Histological studies and monthly distribution of GSI, showed that the GSI values have two peaks; the first and highest in May and the second and smallest in October. The minimum GSI was determined in December. It was found that male Saurida tumbil reach the first sexual maturity at 25.5 cm. Sections with 5-7 mm thick were stained with Hematoxyline-eosin for microscopic examinations. In the histological study, spermatogonial proliferation stage, spermatogenesis, prespermiation and degeneration stages were observed.

This study was carried out to evaluate some biological Reproductive aspects of Sillago sihama, a valuable gonochoristic species living in coastal areas of the Persian Gulf, from August 1997 to September 1998. Forthy fish were caught each month, and their tota11ength, standard length and total weight were measured. Fish were then disected and liver, stomach and gonads were weighted. A piece of gonad samples of different stages of maturity were taken and placed in bouins fixative. Minimum and maximum fish length were 9.8 and 23.5 centimeters respectively. Length-weigth relationship showed isometric growth in this species. Gonadosomatic index (GSI), gastrosomatic index (G I) and hepatosomatic index (HSI) were also measured. GSI was averaged 4.5 in March for females and 1.50 in April for males. Histological evidence showed that this fish has an ovary with free riped ova at the same time and spawn once a year in spring (synchronus). Sex ratio was measured (1 M: 1.2 F), (a=0.05, df=l, X2=5). Size of maturity were 11.4 and 12.6cm for males and females respectively.

In the present investigation, some Reproductive characteristics of Alburnus mossulensis were examined. Sampling of 325 specimens were carried out at monthly intervals from Gamasiab River, Tigris River drainage, western Iran, through the year 2013. Age, sex ratio, fecundity, oocytes diameter, gonadosomatic (GSI), modified gonadosomatic, Dobriyal and hepatosomatic indices were measured. Regression analysis was used to estimate the relations between fecundity and standard length, body weight, gonad weight and age. All of the male with 70. 0mm and female with 75. 0mm in standard length, and all of those older than one year were ripe. The mean egg diameter ranged from 0. 11mm (August) to 0. 84mm (May). Spawning took place in May, when the water temperature was 18 to 22° C. Average GSI values for females at the beginning of the reproduction period (March) and in ripe mature females (May) were 5. 05% and 12. 03%, respectively. The averages of absolute and relative fecundity (g/body weight) were 1920 eggs (± 1025SD) and 99. 03 (± 94), respectively. The absolute fecundity was significantly related to body length and ovary weight.

Pseudotocinclus tietensis is endemic to the Upper Tietê River basin and classified asvulnerable. The Reproductive biology of this species is still unknown, therefore, we investigated itsReproductive strategy and gonad development during its annual Reproductive cycle. The fish werecollected throughout one year, and histology of the gonads, fecundity and oocyte diameter wasconducted. Three phases of gonad maturation were found in males and females (immature, developing, and spawning capable), and the development stages of the gametes were identified withineach stage. In the testes, four stages of gamete development were distinguished: spermatogonia, spermatocytes, spermatids and spermatozoa. During spermiation, the spermatozoa were released intothe tubular lumen and then continued through the efferent ducts. In the ovaries, five stages of gametedevelopment were identified: chromatin nuclear, perinucleolar, yolk vesicle formation, vitellogenicand ripe. The minimum diameter of ovulating oocytes was 297 μm, and the absolute fecundity was64 to 306 oocytes. Males with spermatozoa in the lobular lumen and females with vitellogenic andripe oocytes were found throughout the year. Pseudotocinclus tietensis has asynchronous ovariandevelopment and gametes with fertilization capacity can be eliminated throughout the annual cycle.

Information about the Reproductive biology of the silver barb is essential for conservation and domestication purposes. This study aims to analyze the Reproductive biology of the silver barb in Lake Tempe, South Sulawesi, Indonesia. The aspects of Reproductive biology analyzed include length-weight structure, sex ratio, length-weight relationship, condition factor, first gonadal maturity size (L50), gonadal maturity, and fecundity. This study used primary data, with silver barb fish being caught using gill nets every week from January to July 2023. The total length of the fish was measured using an ichthyometer with an accuracy of 0.1 cm, and the weight was measured using a digital scale with an accuracy of 0.01 g. The gonads were preserved in a 4% formalin solution, and fecundity was calculated using the gravimetric method. The length structure of male ranged from 8.9 to 22.9 cm, and females ranged from 8.9 to 28.5 cm. Males had weights between 21.2 and 183.2 g, and females 21.2 and 312.8 g. The overall sex ratio of males to females was 1:1, while the sex ratio during spawning was 1:3 (polygamy). The length-weight relationship for males and females was W = 0.0234L2.7349 and W = 0.0172L2.8766, respectively. The condition factor for both males and females was 1.02. The first gonadal maturity size for females was 18.3 cm and 19.9 cm for males. Spawning was partial, with fecundity ranging from 253 to 13,398 eggs.