The gametogenic cycle of Scrobicularia plana (Mollusca: Bivalvia) in Mweeloon Bay (Galway, west coast of Ireland)

2006 ◽  
Vol 86 (5) ◽  
pp. 1157-1162 ◽  
Author(s):  
Jean Raleigh ◽  
Brendan F. Keegan
Keyword(s):  
West Coast ◽  
Shell Length ◽  
Developmental Stages ◽  
Gonad Development ◽  
Breeding Cycle ◽  
Gametogenic Cycle ◽  
Broad Agreement ◽  
Northern Latitudes ◽  
Scrobicularia Plana ◽  
Male Sex

The gametogenic cycle of Scrobicularia plana was studied in Mweeloon Bay (Galway, west coast of Ireland) over the periods of February to September 1996 and January to September 1997. Quantitative (reproductive indices and oocytes size) and qualitative (gonad developmental stages) analysis identified a broad annual breeding cycle, with one protracted spawning event occurring from May until September. Early gonad development had begun by January/February. Spawning animals were first recorded at the end of May and continued to mature throughout the summer. The decrease in temperature in September coincided with the end of the spawning season and gonad regression. Although the species is predominantly dioecious, one case of hermaphrodism was recorded. A female to male sex ratio of 1.1:1 was registered. Sexual maturity occurred at a shell length greater than 20 mm; the smallest individual undergoing sexual development had a shell length of 22.4 mm. The timing of the reproductive cycle in S. plana at Mweeloon Bay is in broad agreement with previous findings on the species carried out in northern latitudes.

On the reproduction of the Mediterranean keystone limpet Patella rustica: histological overview

2014 ◽  
Vol 94 (8) ◽  
pp. 1651-1660 ◽  
Author(s):  
Ivana Prusina ◽  
Daria Ezgeta-Balić ◽  
Stijepo Ljubimir ◽  
Tatjana Dobroslavić ◽  
Branko Glamuzina
Keyword(s):  
Reproductive Cycle ◽  
Shell Length ◽  
Histological Analysis ◽  
Developmental Stages ◽  
Gonad Development ◽  
Gonad Index ◽  
Keystone Species ◽  
Males And Females ◽  
Sexually Mature ◽  
High Shore

The reproductive cycle of the high shore limpet Patella rustica is described based on histological analysis as the primary method of staging gonad development. Sex-ratios, shell length at sexual maturity, gonad developmental stages, mean gonad index and oocyte size were investigated. Males and females were found to differ in size distribution, with females becoming more prevalent from ~28 mm onwards. The estimated shell length at which 50% of males were sexually mature was 13.1 mm. Patella rustica has only one reproductive cycle per year with a spawning peak between November and December for both sexes, and gonad redevelopment from January. First data on the size–frequency analysis of oocytes for this species are also presented, concurring with the qualitative analysis of the gonad developmental stages. This study presents updated information on the reproductive cycle of this keystone species and provides the first account of the reproductive biology of P. rustica in the Adriatic Sea.

Breeding biology and movements of Australian sea-lions, Neophoca cinerea, off the west coasst of Western Australia

1992 ◽  
Vol 19 (4) ◽  
pp. 405 ◽  
Author(s):  
NJ Gales ◽  
AJ Cheal ◽  
GJ Pobar ◽  
P Williamson
Keyword(s):  
Breeding Season ◽  
Western Australia ◽  
West Coast ◽  
Metropolitan Region ◽  
Breeding Cycle ◽  
Sea Lion ◽  
The West ◽  
Breeding Sites ◽  
Sea Lions ◽  
Neophoca Cinerea

The Australian sea-lion, Neophoca cinerea, has a 17-18-month breeding cycle on islands off the west coast of Western Australia. Buller, North Fisherman and Beagle Is are the main pupping sites, with several very small colonies (n> 3) at the Abrolhos Is. The 4-5-month pupping seasons are synchronised at North Fisherman and Beagle Is, but the sea-lions from Buller I. breed one month later and those from the Abrolhos Is two months earlier. Pup production and pup mortality were highly variable between seasons over which observations were recorded: 129 pups were born at the main breeding sites in early 1988, the mortality in the first five months was 7.1%, whereas 181 pups were born in late 1989 of which 24.3% died. Pups remain in the vicinity of their natal islands for the first 4-5 months of life before leaving, perhaps on foraging trips, with their mothers. Most return to their natal island, although others haulout on islands up to 27 km away. Some male N. cinerea congregate in bachelor colonies on islands adjacent to the Perth metropolitan region during the non-breeding season and migrate up to 280 km north each breeding season. The status of the isolated, west-coast N. cinerea population is unknown. The current high level of human pressure on sea-lion terrestrial habitats and their food resources indicate a need for further monitoring of this species.

Ampithoe bizseli n. sp. (Crustacea, Amphipoda) from the west coast of Turkey

Zootaxa ◽  
2012 ◽  
Vol 3388 (1) ◽  
pp. 17 ◽  
Author(s):  
MURAT ÖZAYDINLI ◽  
CH. OLIVER COLEMAN
Keyword(s):  
New Species ◽  
West Coast ◽  
Similar Species ◽  
The West ◽  
Male Sex

The new species Ampithoe bizseli from the west coast of Turkey is described. It can be distinguished by a circular ischiumlobe on gnathopod 2 in the male sex from the similar species Ampithoe ramondi where this lobe is slender. Ampithoe bizseli n. sp. appears to occur also on the coast of Tansania.

scholarly journals Sox9-dependent expression of Gstm6 in Sertoli cells during testis development in mice

Reproduction ◽  
2009 ◽  
Vol 137 (3) ◽  
pp. 481-486 ◽  
Author(s):  
Annemiek Beverdam ◽  
Terje Svingen ◽  
Stefan Bagheri-Fam ◽  
Pascal Bernard ◽  
Peter McClive ◽  
...  
Keyword(s):  
Gonad Development ◽  
Cell Lineage ◽  
Somatic Tissue ◽  
Temporal Expression ◽  
Mouse Development ◽  
Adult Mice ◽  
Multifunctional Enzymes ◽  
Male Sex ◽  
Temporal Expression Pattern ◽  
Male Specific

Glutathione S-transferases (GSTs) are an important family of multifunctional enzymes that play a role in the protection of tissues by the detoxification of hazardous and carcinogenic compounds. We found previously that Gstm6 is upregulated in the somatic cells of male mouse fetal gonads relative to female gonads. In this study, we describe the spatial and temporal expression pattern of Gstm6 during mouse development. We show that Gstm6 is predominantly expressed in the reproductive system, at significantly higher levels in XY gonads compared with XX gonads from 11.5 dpc onwards, and remains expressed in the testes in adult mice. Its expression is associated with the Sertoli cell lineage, and is dependent on the expression of the male sex-determining gene Sox9. Our data suggest that Gstm6 plays a male-specific role in gonad development or function, possibly by modulating the exposure of somatic tissue and/or germ cells to endogenous or exogenous toxicants.

The reproductive cycle of the sea urchin Psammechinus miliaris (Echinodermata: Echinoidea) in a Scottish sea loch

2000 ◽  
Vol 80 (5) ◽  
pp. 909-919 ◽  
Author(s):  
Maeve S. Kelly
Keyword(s):  
Sea Urchin ◽  
Annual Cycle ◽  
Developmental Stages ◽  
Food Resource ◽  
Gonad Development ◽  
Market Place ◽  
Spawning Period ◽  
Psammechinus Miliaris ◽  
Population Recruitment ◽  
Time Of Year

The sea urchin Psammechinus miliaris was sampled at monthly intervals from two replicate sites at contrasting locations (littoral and subtidal habitats) on the west coast of Scotland. Samples were collected from November 1995 to October 1997. A study of gonad development showed a clearly defined annual cycle of gametogenesis with a single spawning period. Gonad indices (GIs) varied between locations, between sites at the same location and between study years. Gonad indices were maximal prior to the onset of the spawning period in June and July. Ripe gametes were shed by dissected urchins from June to September in 1996 and June to August in 1997 coinciding with the time of year when the gonad colour was best in terms of what is desired in the market place. Over winter the GIs were very low and gonads became very dark in colour. Higher summer GIs in the urchins from one littoral site suggested that the urchins there had a seasonal influx of a more nutritious or more abundant food resource. Histological determination of the reproductive state showed that for these food-limited populations high GIs do equate with the spawning period. The gametogenic cycle fits the six stage pattern described for other echinoid species. In females oocytes of various developmental stages were present throughout the annual cycle. Recruitment to the littoral location was monitored over two seasons by quantifying the number of urchins with a test diameter <5 mm appearing in the population. Recruitment appeared variable between sites and between seasons suggesting that the collection of juveniles resulting from natural settlement may not be a reliable alternative to hatchery produced spat. Although P. miliaris has commercial potential when in cultivation, this study provided no evidence of an opportunity for a commercial fishery.

scholarly journals Gonad development in females of fiddler crab Uca rapax (Crustacea, Brachyura, Ocypodidae) using macro and microscopic techniques

2007 ◽  
Vol 97 (4) ◽  
pp. 505-510 ◽  
Author(s):  
Daniela da Silva Castiglioni ◽  
Maria Lucia Negreiros-Fransozo ◽  
Laura S. López Greco ◽  
Aron F. Silveira ◽  
Sérgio O. Silveira
Keyword(s):  
Developmental Stages ◽  
Fiddler Crab ◽  
Morphological Changes ◽  
Gonad Development ◽  
Morphological Characteristics ◽  
Microscopic Analysis ◽  
Follicle Cells ◽  
Gonad Maturation ◽  
Secondary Stage ◽  
Macroscopic Classification

The morphology of the ovaries in Uca rapax (Smith, 1870) was described based on macroscopic and microscopic analysis. Females were collected in Itamambuca mangrove, Ubatuba, state of São Paulo, Brazil. In the laboratory, 18 females had their ovaries removed and prepared for histology. Each gonad developmental stage was previously determined based on external and macroscopic morphology and afterwards each stage was microscopically described. The ovaries of U. rapax showed a pronounced macroscopic differentiation in size and coloration with the maturation of the gonad, with six ovarian developmental stages: immature, rudimentary, developing, developed, advanced and spent. During the vitellogenesis, the amount of oocytes in secondary stage increases in the ovary, resulting in a change in coloration of the gonad. Oogonias, primary oocytes, secondary oocytes and follicular cells were histologically described and measured. In female’s ovaries of U. rapax the modifications observed in the oocytes during the process of gonad maturation are similar to descriptions of gonads of other females of brachyuran crustaceans. The similarities are specially found in the morphological changes in the reproductive cells, and also in the presence and arrange of follicle cells during the process of ovary maturation. When external morphological characteristics of the gonads were compared to histological descriptions, it was possible to observe modifications that characterize the process in different developmental stages throughout the ovarian cycle and, consequently, the macroscopic classification of gonad stages agree with the modifications of the reproductive cells.

Reproduction of the turban shell Turbo torquatus Gmelin 1791 (Mollusca : Gastropoda), in New South Wales, Australia

2002 ◽  
Vol 53 (1) ◽  
pp. 85 ◽  
Author(s):  
D. W. Ward ◽  
A. R. Davis
Keyword(s):  
Reproductive Cycle ◽  
Developmental Stages ◽  
New South ◽  
Gonadosomatic Index ◽  
New South Wales ◽  
Gonad Development ◽  
Gonadal Development ◽  
Small Scale ◽  
Frequency Distributions ◽  
South Wales

The Sydney turban shell Turbo torquatus is the focus of a small-scale commercial fishery in New South Wales. Effective management requires knowledge of the reproductive biology, yet this is lacking for NSW waters. The reproductive cycle was investigated at three localities on the southern New South Wales coast. Samples of T. torquatus were collected monthly at Wollongong, Ulladulla and Eden from February 1996 until August or December 1997. The reproductive cycle was investigated by three methods: monthly determination of a gonadosomatic index, estimation of oocyte size-frequency distributions and classification of female gonads into developmental stages following histological sectioning. Males and females within a population underwent synchronous gonad development and spawning. Spawning events were often protracted over a period of several months with females in various stages of gonadal development. Two spawning events occurred each year, with a spawning event in autumn–winter and another in spring–summer. These events were asynchronous among the three localities, and partial spawning appeared to be a common occurrence. Owing to variation in the timing of spawning between populations separated by a distance as small as 15 km, seasonal closures to protect spawning stocks are unlikely to be effective.

Heavy Metals in the Burrowing Bivalve Scrobicularia Plana From Contaminated and Uncontaminated Estuaries

1978 ◽  
Vol 58 (2) ◽  
pp. 401-419 ◽  
Author(s):  
G. W. Bryan ◽  
L. G. Hummerstone
Keyword(s):  
Heavy Metals ◽  
Life Span ◽  
Mytilus Edulis ◽  
Shell Length ◽  
Estuarine Sediments ◽  
Biological Availability ◽  
The South ◽  
Scrobicularia Plana ◽  
Deposit Feeding

Analysis of the deposit-feeding bivalve Scrobicularia plana (da Costa) has been proposed as a method of assessing the biological availability of heavy metals in estuarine sediments (Bryan & Hummerstone, 1977; Bryan & Uysal, 1978). Scrobicularia has a number of attributes which are useful in this type of indicator: (i) it is common in many British estuaries, particularly in the south, and often penetrates much farther upstream than other common bivalves such as Mytilus edulis; (ii) it is a convenient size for analysis and, during its life span of perhaps 10 years, reaches a shell length of 40-50 mm (Green, 1957; Hughes, 1970); (iii) it is a good accumulator of metals and appears to reflect changes in their biological availability.

The use of artificial substrates in monitoring mussel (Mytilus edulis L.) settlement on an exposed rocky shore in the west of Ireland

1990 ◽  
Vol 70 (2) ◽  
pp. 371-380 ◽  
Author(s):  
P.A. King ◽  
D. Mcgrath ◽  
W. Britton
Keyword(s):  
Mytilus Edulis ◽  
West Coast ◽  
Shell Length ◽  
Rocky Shore ◽  
Artificial Substrates ◽  
Filamentous Algae ◽  
The West ◽  
Settlement Size ◽  
West Of Ireland

Artificial substrates were used to monitor Mytilus edulis L. settlement on an exposed rocky shore at Ballynahown, on the west coast of Ireland, from August 1984 to September 1985. Flat nylon domestic pan scourers proved to be good collectors of mussel recruits. The appearance of new modes of 300 µn shell length at times of increasing density of colonising mussels indicated direct settlement of mussel larvae from the plankton onto the pads. These modes appeared in September 1984, May 1985 and August 1985. Direct settlement periods followed the known main spawning times of adult mussels at the study site, March-April and July-August, and are consistent with settlement times ob-served on filamentous algae and adult beds on the same shore. Results from the study show that mussels of primary settlement size, 250–400 im shell length, were available to colonise newly deployed pads throughout the investigation. Furthermore, cohorts of larger mussels recruited to the pads during much of the year. The possible source of these recruiting mussels is discussed.

scholarly journals Reproductive ecology of Atherina hepsetus L. (Pisces: Atherinidae) of the west coast of Crimea

2016 ◽  
Vol 1 (2) ◽  
pp. 43-50
Author(s):  
Yu. V. Samotoy ◽  
G. V. Zuev
Keyword(s):  
West Coast ◽  
Gonadosomatic Index ◽  
Gonad Development ◽  
The West ◽  
The Subject ◽  
Males And Females ◽  
The Individual ◽  
First Time ◽  
Sea Fish ◽  
Calendar Dates

Atherina hepsetus L. (Atherinidae) is a numerous pelagic species in the Azov – Black Sea basin and the subject of fishery in some areas. However, information about biology and ecology of this species has been very scanty and fragmentary until nowadays. This work is devoted to the study of interannual and seasonal variability of some individual and population reproductive parameters of A. hepsetus of the west coast of Crimea in theBlack Sea. Fish were caught by trap-nets during 2010–2014 with intervals for 2–3 times per month. 2043 specimens were studied. Concepts of general, population and mass reproductive periods were studied for the first time; interannual changes of their duration and calendar dates of beginning and end of spawning were established. The intensity and spawning seasonal dynamics, gonad development in males and females were studied. The individual and population values of gonadosomatic index were identified. The range of reproductive water temperature variability (8.5–14.5 °C) and the zone of the most favorable spawning temperature (9–12 °C) were found.

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