This study aimed to analyze the reproductive cycle of the crab Hepatus pudibundus (Herbst, 1785). The crabs were collected in Ubatuba, SP (23 degrees 26'S and 45 degrees 02'W) monthly from the July, 1992 to June, 1993. Samplings were performed with an "otter trawl". In the laboratory the crabs were numbered, sexed and measured for their maximum carapace width. The gonad developmental stage and ...

Reproductive or neotenic soldiers of the Archotermopsid Zootermopsis nevadensisnevadensis (Hagen) are compared to sterile soldiers and primary male reproductives. Several head capsule morphometrics correlate significantly with gonad size across all forms and both sexes of soldiers. The easily observed field character of ratio of mandible length to labrum length is a consistent and reliable feat...

Profiles for plasma gonadotropin, estradiol, and vitellogenin were obtained in female brown trout during the seasonal reproductive cycle. The accumulation of yolk lipophosphoprotein (phosvitin) in the gonad was also followed. Plasma estradiol and vitellogenin concentrations rose progressively and parallel increases in ovary yolk phosvitin were observed. Gonad development continued while plasma ...

The effect of the microalgae Haematococcus pluvialis and Chorella zofingiensis, and synthetic astaxanthin on the gonad of the sea urchin Anthocidaris crassispina was studied. The basal diet was supplemented with H. pluvialis, C. zofingiensis, or synthetic astaxanthin, at two levels of astaxanthin (approximately 400 mg/kg and 100 mg/kg), to obtain the experimental diets HP1, HP2, CZ1, CZ2, AST1,...

Proses induk lele (Clarias gariepinus Burchell) betina menjadi matang gonad secara alami memakan waktu hingga 2-3 bulan, dengan tingginya permintaan benih diperlukan percepatan proses pematangan agar dapat terpenuhi, salah satunya melalui pemberian hormon ethinylestradiol. Kandungan optimum ethinylestradiol pada tubuh akan mempercepat vitellogenesis sehingga memacu pertumbuhan oosit dan kematan...

Gonad characteristics and reproductive cycle in the acmaeid Collisella subrugosa from Northeastern Brazil were investigated. The individuals were collected monthly from February 1993 to April 1994 at Farol do Mucuripe Beach, Fortaleza, Ceará, Brazil. There is no external characteristic on the shell and the soft body structures except the gonad that allows sex differentiation. The gonad of limpe...

The functional, nutritional, and antioxidative properties of hydrolyzed herring and herring byproducts (head and gonad) were evaluated. All freeze-dried herring fish protein hydrolysate (FPH) powders were light yellow and contained 77% to 87% protein. The degree of hydrolysis was 18.3%, 13%, 13%, and 10.1%, respectively, for head, whole fish, body, and gonad after 75 min digestion. All FPH powd...

The creation of sexual dimorphism in the gonads is essential for producing the male and female gametes required for sexual reproduction. Sexual development of the gonads involves both somatic cells and germ cells, which often undergo sex determination by different mechanisms. While many sex-specific characteristics evolve rapidly and are very different between animal species, gonad function and...

This study investigated the effect of different photoperiods (14L: 10D, 12L:12D and 10L:14D) on the gonadal development and GtH mRNA expression in the pituitary of damselfish. The results showed that gonadosomatic index (GSI) was significantly lower in shot photoperiod (10L:14D), in comparison with other photoperiodic group during the spawning season. After 60 days treatment, histological analy...

The gonad in Caenorhabditis elegans is an important model system for understanding complex morphogenetic processes including cellular movement, cell fusion, cell invasion and cell polarity during development. One class of signaling proteins known to be critical for the cellular events underlying morphogenesis is the Rho family GTPases, particularly RhoA, Rac and Cdc42. In C. elegans orthologues...