جستجوی مقالات مرتبط با کلیدواژه "رسیدگی جنسی" در نشریات گروه "زیست شناسی"

The Caspian kutum is one of the most important economic and native species of the Caspian Sea. Kisspeptin neurons act as a central processor in the transmission of peripheral signals to gonadotropin receptor (GnRH) neurons. To investigate the role of kisspeptin, especially Kiss1 in the reproduction of the Caspian kutum, the expression of the Kiss1 gene in brain tissue was evaluated using real-time PCR. For this purpose, 36 pieces of fish were caught from Anzali shores from November 1997 to May 1998 with an average weight of 650±50 g and a length 35.5±0.2 cm and brain tissue was separated. After extraction of total RNA and cDNA synthesis from brain tissue, expression of the Kiss1 gene was performed using real-time PCR technique by reference gene-actin-β. Data were evaluated using one-way analysis of variance (ANOVA) and Tukey post-test and 95% confidence level and the significant difference in expression of the Kiss1 gene was calculated per month in both sexes. The results showed that the expression level of the Kiss1 gene in the brain tissue of male and female fish showed a significant difference in different months (p< 0.05). The highest expression of the Kiss1 gene in both sexes was reported in May during the Caspian kutum spawning. In addition, morphohistology of gonads showed that the highest sexual maturity was from March to May. In conclusion, it seems that it can be stated that Kiss1 has the highest level of expression in the months when the Caspian kutum reaches its sexual maturity.

Swan mussel, Anodonta cygnea, is a freshwater bivalve inhabitant of Anzali wetland, which population is in danger due to pollution and habitat destruction by human manipulation. In the present study, some reproductive traits of this species were evaluated for one year period using microscopic and biometric studies. The mean length was 10.6±0.1cm, the mean width was 6±0.04cm, the mean height was 4±0.04cm, the mean weight was 132±3g and the mean age was 6±0.1 years old. In all shells, two sexes were separated. There was no external feature for sex determination. The frequency of female was 1.5 times that of male. The mean diameter of mature oocyte and sperm were 139.95±8.1 and 4.5±0.26μm, respectively, and the mean area of ​​them was 15255.58±1834.4 and 9.1±1.16μm2, respectively. The mean fecundity was 107844.6±20621.9. Both of male and female gonads were in developing phase in spring (May and June) and in summer (July and August). The spawning stage occurred in the fall and the post-spawning stage in the winter. The development of glochidia were completed in January and the release of them from the gill were occurred between January and March.

Determination of reproductive status and knowledge in physiological situations of fish is essential to manage brooders. So, in this study, the efficacy of skin mucosal layer was investigated as the important source of biochemical and also less-invasive method to know goldfish reproductive status. In our research, fish sampling was carried out during five months and according to the histological analysis of gonad, the fish were divided into 5 stages: primary growth (I), cortical alveoli (II), early-vitellogenesis (III), late-vitellogenesis (IV) and spawning (V). Total protein, calcium, lipids (cholesterol and triglyceride) and alkaline phosphatase (ALP) levels of mucus and plasma were measured and compared. Protein levels of mucus were significantly increased during late-vitellogenesis (P < 0.05). Mucosal calcium levels were lower than plasma. Cholesterol and Triglyceride of mucus showedsignificant enhancing during the late-vitellogenesis (P < 0.05). ALP activity was elevated in mucus more than plasma. In histological studies, the analysis of gonadosomatic index showed significant positive correlation between this factor and plasma protein as well as mucus (P < 0.01). ALP was the appropriate indicator to distinguishing vitellogenesis and spawning stages. In summary, the results of this study indicated that the biochemical factors in mucus is measurable and be considered as a less-invasive tool and alternative blood for monitoring the endocrine response, reproductive indices, and sexual stages, especially in the vitellogenesis stages.

Reproductive biology of Siah mahi, Capoeta capoeta intermedia was studied by examining 330 individuals collected between November 2012 to October 2013, by regular monthly collections in the Shapour River, Iran. Overall female-male (F-M) sex ratio was 1:1.66 and their total length (TL) was 15 to 29 cm (19.83 ± 2.3) and 15.5 to 26 (19.85 ± 2) cm for females and males, respectively. The minimum and maximum weight of female and male calculated 36 to 250 g (93.4 ± 38) and 36 to 183.27 gr (87.24 ± 25.9), respectively. Reproductive period for this species is from February to June when GSI is considerably higher than the rest months. The absolute fecundity (AF) of siah mahi ranged from 105 to 8134 eggs per fish, with mean AF value of 2252.6±310 eggs per fish, varying considerably at given length and weight and there was a positive linear correlation between AF with total weight (p

In this study, the effect of different dietary nucleotide levels (0, 0.2, 0.4 and 0.6%) was investigated on growth indices and some haemolymph biochemical parameters of Litopenaeus vannamei female broodstock during 30 days.hemolymph was sampled in three times, at the first day of the trial, 21 days (before eyestalk ablation) and 30 days (9 days after eyestalk ablation) after starting the feeding trial. In experimental period, water parameters including temperature, dissolve oxygen, salinity and pH recorded daily as 27.79 ± 1.24 ˚C, 5.78 ± 0.41 ppm, 31.82 ± 3.1 ppt and 7.9 ± 0.18, respectively. haemolymph biochemical parameters of female broodstock including glucose, total cholesterol, triglyceride, calcium, albumin, total soluble proteins, high density lipoprotein and low density lipoprotein measured in three phases (start of feeding, 21 [pre eyestalk ablation period] and 30 days after start feeding) by biochemical standard methods. the results showed that body weight increase, specific growth rate and daily growth rate in samples treated by dietary nucleotide showed no significant difference (p > 0.05) compared to control group. analysis of biochemical heamolymph showed that the glucose, total cholesterol, triglyceride, albumin, total protein were significant increasing (p

Sea cucumber species are commercially important in the world. This study explored the reproductive biology of sand fish sea Cucumber in Qeshmisalnd in the Persain Gulf for a year, from December 2012 to November 2013. The macroscopic study intended to examine the features such as gonad color, gonad weight, their length and diameter, and specify the spawning season. Microscopic examinations included histological studies of Hemotoxylin and Eosin (H&E) stained texture slides. We measured early, middle and final stages of gonad diameter by and eyepiece micrometer optimize. Gonad color of male at this stages is white – creamy and gonad color of female stage is orange – red. Based on these criteria, five stages of maturity were determined for both sexes. The result showed that winter is the spawning season in Qeshm area. The correlationn between gonad and different seasons shows meaningful difference (p

Inroduction & Pike(Esox Lucius) is one of the important economical fish in Caspian Sea region which is living in areas such as wetlands and rivers in which covered with aquatic plants. The reproduction of this fish naturally occurs in freshwater ecosystems. The aim of this study was the investigation in ovarian development stages of pike broodstocks, which is the important indicator for fish reproduction biology and also there is little documents available about it.Histological pictures were employed for growth survey and evolution of gonads in pike. In order to histology and determination of sexual maturation stages, 50 ovaries were studied. Fixed Samples were studied by light microscope.The sexual maturation stages showed that ovaries of pikes were in stages II (spring and summer), III (summer and autumn), IV and V (winter). Also, the highest value of absolute fecundity determined as much as 13609.347 in autumn and the highest value of Gonadosomatic index determined as much as 4.063 at the first half of winter. The results showed that pike is spawning at once.