ABSTRACT
Background: Maturity of silver carp [Hypophthalmichthys molitrix] ovary takes place at 2-8 years old and it is depends on photoperiod and environmental water temperature
Objectives: The aim of this study was to identify macroscopical and microscopical structure of silver carp ovary in two categories of body weight, total body length and at 2 and 4 years old in Khuzestan province climatic conditions
Methods: 20 silver carp ovaries were studied in two groups: Group 1[G1]: 10 fish with total body length 46 +/- 1.33 Cm and weight 1050 +/- 0.09 grand approximately 2 years old. Group 2[G1]: 10 fish with total body length 86 +/- 3.64 Cm and weight 5460 +/- 800 gr and approximately 4 years old. For the histometrical studies, 5-6 micro sections were made by routine paraffin embedding method and stained by H and E and PAS
Results: Microscopic results showed that ovaries of G1 covered by a thin loose connective capsule which numerous of egg-bearingtrabecula extended from capsule into ovaries. These trabecula contained primary germ cells, oogonium, chromatin nocleolus, perinocleolus and cortical alveolus follicles. Ovaries of G1 do not have yolk and mature follicles. But in ovaries of G2, growth and mature follicles were observed and mature follicles were most follicles. Histometrical results showed that there are not a significant differences in diameter of follicles, oocytes and oocytes nucleolus in G1 and 2. The maximum and minimum diameter of follicles were seen in mature and chromatin nucleolus follicles respectively. The Zona plucida thickness was increased from corticalalveolus [1.53 +/- 1.11 mm] to mature follicles [6.88 +/- 0.21 mm] significantly [p<0.05]
Conclusions: The most interesting finding of this study is that in Khuzestan Province climate, the ovary of silver carp fish in G1, with average weight 1050 +/- 0.09 gr and total length 46 +/- 1.33 Cm and approximately of 2 years old is immature but ovary of G2 with average weight of 5460 +/- 800 gr and total length 86 +/- 3.64 Cm and approximately 4 years old is mature
ABSTRACT
Quantitative microscopic structure of testis in adult Arabian rams, raised under closed grazing system in Khuzestan province of Iran, was studied in four seasons over a one year period. For this purpose, thirty adult rams were randomly selected and the live weight and scrotal circumference of rams were recorded. At the beginning of each season, among the study group, four rams were randomly selected, slaughtered and their left testes were removed and weighed. For microscopic studies, tissue samples were excised from the left testes, fixed in Bouin's solution and embedded in paraffin. Cross-sections [5 micro m thickness] were stained with haematoxylin-eosin and evaluated with quantitative techniques. The results showed that scrotal circumferences, weight and volume of testis varied significantly throughout the year, with the lowest values in early summer [P<0.05]. Seminiferous tubule diameter was highest in early winter [220.97 +/- 12.15 micro m]. Also, relative and total volumes of seminiferous tubules and germinal epithelium gradually increased during the summer and autumn, with highest values in early winter. Higher relative volume of seminiferuos tubuli lumina [P<0.05] was found in early summer [%12.15 +/- 0.35]. Lower relative volume of interstitial tissue [P<0.05] was found in early winter [%15.70 +/- 0.49]. Scrotal circumference was significantly correlated with the seminiferous tubule diameter and the total volume of seminiferous tubules [r = 0.70, P<0.01]. The results indicated that the stereological structure of testis in Arabian rams raised under closed grazing system in the Khuzestan province of Iran is highly affected by season