scholarly journals Uterine fluid composition of the dwarf ornate wobbegong shark (Orectolobus ornatus) during gestation

2011 ◽  
Vol 62 (6) ◽  
pp. 576 ◽  
Author(s):  
Megan T. Ellis ◽  
Nicholas M. Otway

Low fecundity in chondrichthyans makes them extremely susceptible to fishing, so understanding the various reproductive strategies in this group is vital for management. Knowledge of the uterine fluid (UF) composition throughout gestation is fundamental to this understanding, yet is restricted to a few species. This study focussed on the UF composition of the wobbegong (Orectolobus ornatus), which inhabits coastal waters off eastern Australia. The UF was quantified throughout pregnancy. Fluids surrounding uterine eggs had a complex composition, with mean urea (98.48 mmol L–1), sodium (560.25 mmol L–1) and potassium (13.93 mmol L–1) concentrations significantly greater than those in seawater. A change in composition, from complex to simple, occurred after 3–4 months gestation. Major electrolyte concentrations then resembled seawater for the remainder of gestation, suggesting the flushing of the uteri with seawater and evidenced by fluctuating low levels of urea. The gestation period reflected the time for metabolism of yolk stores, osmotic and ionic adjustment, development of functioning immunological systems and prevention of external yolk sac damage. Our study is the first documentation of UF composition for a wobbegong shark and increases understanding of its reproductive biology.

1960 ◽  
Vol 11 (3) ◽  
pp. 365 ◽  
Author(s):  
CW Stump ◽  
JP Robins ◽  
ML Garde

The material consists of 20 embryos (5-30 mm) and two foetuses (63 mm and 90 mm) collected at whaling stations on Moreton and Norfolk Islands (latitude 27� 11'S. and 29� 5' S. respectively) during late August, September, and early October in 1952-53-54 and 1956. The consecutive series permitted the study of membrane formation and organogenesis. Younger embryos are found in grooves between the folds of endometrium in a constant site in that uterine horn associated with the ovary containing the recent corpus luteum. Older embryos and the early foetus are adapted to lie freely in the uterine fluid, and are devoid of any mechanism for apposition or attachment to the endometrium. Variation in the sequence of the association of the components of the umbilical cord provides suspensory structures for the amnion and yolk sac, and for the embryo a bifid ligament, retained in the early foetus for attachment of the foetal membranes. In the younger foetus the allantoic duct drains the nephric secretion into the uterine cavity. In the older foetus chorionic villi are present. The bifid suspensory ligament forms the major part of the distal region of the umbilical cord. The allantoic duct is reunited with the allantoic sac. Amniogenesis is by folding. During the embryonic period the chorio-amniotic connection forms a suspensory ligament. The yolk sac, attached by a novel ligament to the amnion, is large and functional in the embryo. In the foetus vascular splanchnopleure is present in a tubular form. A rete system develops in the embryo.


2018 ◽  
Vol 9 (1) ◽  
pp. 31
Author(s):  
Ismaïla NDIAYE ◽  
Alassane SARR ◽  
Alioune FAYE ◽  
Modou THIAW ◽  
Malick DIOUF ◽  
...  

In this study, a total of 1068 specimens Sardinella aurita of which 553 females and 515 males were examined. The objectif of this study was to determine the reproductive parameters of Sardinella aurita. The sex ratio was significantly in favor of females (55%). The size at first sexual maturity was estimated at 18.9 cm for females and 18.0 cm for males. The monthly variation of sexual maturity stages and gonado-somatic index (GSI) allowed to locate the reproduction periods from February to June and from September to December. The mean absolute fecundity was estimated at 110.794 ± 7582 oocytes whereas relative fecundity was about 422 ± 26 oocytes per gram of female.


2016 ◽  
Vol 74 (3) ◽  
pp. 103-109 ◽  
Author(s):  
Ouratul Edritanti ◽  
Achmad Farajallah ◽  
Yusli Wardiatno

Abstract Emerita emeritus is an abundant species in Bengkulu coastal waters, but the knowledge of its reproductive biology is poor. The present study was conducted to elucidate the reproductive aspects of ovigerous female E. emeritus, including fecundity, egg volume and reproductive output. This study was conducted between January 2015 and January 2016 in Bengkulu coastal waters, Indonesia. Samples were collected manually using shovels and hands. The results showed that ovigerous females occurred every month. Fecundity increased significantly in ovigerous females proportional to the size. No correlation was shown between sea surface temperature and egg production. Fecundity and reproductive output decreased throughout the embryonic development.


Author(s):  
P. A. Tyler ◽  
S. L. Pain

Examination of the reproductive biology of three closely related sympatric astropectinid asteroidshas revealed two distinct reproductive strategies. In Plutonaster bifrons and Dytaster insignis the gonads are serially arranged and open at gonopores located at the tip of genital papillae found on the dorsal arm surface between the bases of the paxillae. The ovaries of these species produce numerous small (ca. 120/«n diameter) eggs which in Plutonaster bifrons appear to show a distinct synchrony of production. Initiation of gametogenesis occurs in June to August of each year with oocyte growthcontinuing until March with a spawn-out in the period March to early June. In specimens where spawningdoesnot occur, there would appear to be internal oocyte degeneration, or after spawning relict oocytesundergo phagocytosis. In males initiation of spermatogenesis may occur in August/September of eachyear but after this synchrony of sperm development is not evident. In Psilaster andromeda gonads are located at the base of the arms and each gonad opens at a single gonopore. A number of small (<300 /«n) oocytes are produced by each gonad. Some of these are phagocytosed and some undergo vitellogenesis and grow to a maximum size of 950 fim before being spawned. Unspent oocytes undergo internal degeneration. In neither females nor males is there any evidence of reproductive synchrony. From these egg sizes, fecundities and gametogenic strategies, we infer indirect planktotrophic development for Plutonaster bifrons, the transfer of a seasonal surface production to deep water providing a food source for developing larvae. The egg size and or close to the sea-bed, as there is no evidence of brooding in this species.


1973 ◽  
Vol 21 (2) ◽  
pp. 171 ◽  
Author(s):  
M Yadav ◽  
M Eadie

Prenatal and precolostral newborn quokkas, S. brachyurus, had no immunoglobulins in their serum. Immunoglobulins were not detected in the yolk-sac fluid, the amniotic fluid, or the allantoic fluid, but were present in the uterine fluid, the colostrum, and milk whey. Immunoglobulins were present in the serum of neonatal quokkas that had suckled for at least 24 hr. Initial immunization of a female with Salmonella adelaide flagella and bacteriophage 0 x 174 antigen resulted in high titres of antibodies in her blood 1 week later, but there was a lag of less than 1 week before anti-S. adelaide agglutinins and a lag of 2 weeks before antiphage antibodies were detectable in the serum of the suckling pouch young. A further delay of 2 weeks occurred before serum antibody titres were as high in pouch young as they were in the mother. At no time in development did antibody titres in the sera of pouch young exceed those of the mother. The ability to absorb antibody in the gut ceased 2-3 weeks after the 6-month-old young left the pouch.


2003 ◽  
Vol 60 (6) ◽  
pp. 1335-1341 ◽  
Author(s):  
Ana Veríssimo ◽  
Leonel Gordo ◽  
Ivone Figueiredo

Abstract A total of 871 females (76–122 cm) and 86 males (68–100 cm) of Centroscymnus coelolepis caught in Portuguese mainland waters were examined for reproductive characteristics. One hermaphroditic individual of 95 cm was found. Males were few in numbers and dominated by immature specimens. Female length at first sexual maturity was 98.5 cm. Mean ovarian and uterine fecundity were 13.2 oocytes per female and 9.9 embryos per pregnant female, respectively. Total length of embryos with completely absorbed external yolk sacs ranged between 233 and 300 mm. Sex ratio (F/M) of embryos with completely absorbed external yolk sac was 0.9. All stages of reproduction were found during the 12-month sampling period. Results were compared with those from other regions. A hypothesis is formulated on the existence of several regional populations based on morphometric and reproductive parameters observed in different areas.


2013 ◽  
Vol 37 ◽  
pp. 717-722 ◽  
Author(s):  
Akbar ABASZADEH ◽  
Yazdan KEIVANY ◽  
Nasrollah Mahboobi SOOFIANI ◽  
Ali FALAHATIMARVAST

1989 ◽  
Vol 257 (4) ◽  
pp. R732-R737 ◽  
Author(s):  
Z. Arad ◽  
U. Eylath ◽  
M. Ginsburg ◽  
H. Eyal-Giladi

The aim of this study was to characterize the dynamic changes in uterine fluid composition and acid-base status during shell calcification in the chicken. Uterine eggs at timed intervals were manually aborted and the accompanying fluid collected and analyzed for composition of osmolytes, enzymes, and acid-base parameters. Blood samples were analyzed for comparison. No considerable change in blood gases took place in relation to residence time of the calcifying egg in the uterus. A significant acidosis occurred at latter stages. Only minor changes were revealed in plasma osmotic and biochemical composition throughout egg calcification. In contrast, major changes were revealed in uterine fluid composition and acid-base status during calcification. The most prominent phenomenon was the sharp increase in CO2 partial pressure, from 82.2 Torr at 0 h to 132.8 Torr at 10 h. As bicarbonate concentration remained almost stable, fluid pH dropped from 7.412 to 7.250 within this stage. Uterine fluid sodium and chloride concentrations and osmolality dropped significantly in the course of calcification, whereas potassium concentration significantly increased. A sharp increase in glucose, calcium, and magnesium concentrations was measured in the early stages of calcification. These findings are discussed in relation to existing models for transport mechanisms of the uterine epithelial tissue. The comprehensive picture that emerges from the present study should enable future application in establishing a self-contained culturing system in vitro for studies of embryonic development.


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