scholarly journals Population structure and reproductive cycle of the commercial sea cucumber Holothuria mexicana in Belize

2018 ◽  
Vol 66 (4) ◽  
Author(s):  
Arlenie Rogers ◽  
Jean-François Hamel ◽  
Annie Mercier
Keyword(s):  
Sex Ratio ◽  
Protected Areas ◽  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Sea Cucumber ◽  
Size Structure ◽  
Natural Populations ◽  
Gonad Index ◽  
Size At Sexual Maturity ◽  
Spawning Periods

The population and reproductive biology of the commercial sea cucumber Holothuria mexicana (Ludwig, 1875) was studied in Southern Belize (Caribbean Sea), including the sex ratio, size at sexual maturity and reproductive cycle, as well as the size structure among habitats located inside and outside protected areas. Individuals found inside marine protected areas were consistently larger than individuals found outside these boundaries. The male:female sex ratio was 1.1:1.0 with a unimodal size distribution composed mainly of sexually mature individuals (87 %). Size at sexual maturity was established to be ~10 cm based on measures of gamogenetically mature individuals during the peak of the gametogenic maturity period. Juveniles and small adults measuring ≤ 15 cm (13 %), were collected exclusively in sandy and muddy areas of seagrass habitats associated with mangroves. Larger adults were commonly found on hard substrates in both seagrass-associated and coral-reef-associated habitats. Based on histology and gonad indices, the first sign of early gametogenesis was detected in August in both sexes. Gametes developed and matured throughout the colder months between November and February. Decreases in gonad index in both years suggest annual spawning, starting in March-April 2014 (single major event) and March-April and July-August 2015 (two smaller events) for both males and females. The spawning periods were correlated with warmer or increasing temperatures, low rainfall and increasing or high chlorophyll-a concentrations. These data will hopefully guide management and protection of the natural populations of H. mexicana, which are already suffering from overfishing in Belize and neighboring countries. 

scholarly journals Population structure and reproductive characteristics of the silky shark Carcharhinus falciformis (Müller & Henle, 1839) (Carcharhiniformes: Carcharhinidae) off the coast of Oaxaca, Mexico

2017 ◽  
Vol 44 (3) ◽  
pp. 513-524
Author(s):  
María del Carmen Alejo-Plata ◽  
Miguel Ángel Ahumada-Sempoal ◽  
José Luis Gómez-Márquez ◽  
Adrián González-Acosta
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Seasonal Changes ◽  
Sexual Maturity ◽  
Size Structure ◽  
Landing Sites ◽  
Silky Shark ◽  
Oceanic Species ◽  
Carcharhinus Falciformis ◽  
Gravid Females

Carcharhinus falciformis is an abundant oceanic species, which occurs in equatorial and tropical zones, with an important catch in the Atlantic and Pacific coasts of Mexico. Samples were taken from December 2000 to December 2007 in four landing sites of the artisanal fleet on the coast of Oaxaca. During the period of study 1236 specimens (602 females and 634 males) of C. falciformis were registered. Total length (TL) ranged from 49 to 217 cm for females (mean = 111.3 cm) and from 59 to 265 cm for males (mean = 111.7 cm). The sex ratio of females to males was 1:1 ( 2 0.05 = 0.78, P > 0.05). The present data suggest a size at first sexual maturity of about 184.8 cm TL for females and 178.5 cm TL for males. The catches were composed mainly of young. In the 52 gravid females examined, the average number of embryos per female was seven; with a range of 3-14 embryos. Mean TL of embryos ranged from 10 to 66 cm with evidence of seasonal changes in the size structure. Results obtained showed that C. falciformis gives birth most of the year, with the highest proportion of births during the rainy season (May to October).

scholarly journals Seasonal variations in the population biology of Salmostoma bacaila (Cyprinidae) from a tributary of the Payra River, Bangladesh

2019 ◽  
pp. 113-119
Author(s):  
Ahamed Ahamed ◽  
Faruque Ahmed Zoarder ◽  
Jun Ohtomi
Keyword(s):  
Sex Ratio ◽  
Seasonal Variations ◽  
Population Biology ◽  
Sexual Maturity ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Spawning Season ◽  
Frequency Distributions ◽  
Size At Sexual Maturity ◽  
Management And Conservation

Some biological parameters of Salmostoma bacaila – including sex ratio, length-frequency distributions (LFDs), size at sexual maturity, spawning season, length-weight relationships (LWRs) and condition factor – were studied. Samples were collected seasonally during June 2017 to May 2018 from a tributary of the Payra River. The overall sex ratio was significantly different from the expected value of 1:1 (p < 0.001), in favour of male specimens. Females were significantly larger than males. Size at sexual maturity was estimated at 7.6~7.7 cm total length. Seasonal variations in the gonadosomatic index (GSI) indicate that the main spawning season is from spring to summer. The LWRs showed negative allometric growth in both sexes, but with clear seasonal variation. Fulton’s condition factor varied in both sexes and was attributed to variations in GSI with maturity. The fin¬dings of this study will be helpful for management and conservation of S. bacaila populations.

Reproductive cycle and size at sexual maturity of the commercial whelk Buccinum isaotakii in Funka Bay, Hokkaido, Japan

2003 ◽  
Vol 83 (6) ◽  
pp. 1287-1294 ◽  
Author(s):  
Anthony S. Ilano ◽  
Katsuaki Fujinaga ◽  
Shigeru Nakao
Keyword(s):  
Seminal Vesicle ◽  
Digestive Gland ◽  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Reproductive Organ ◽  
Egg Laying ◽  
Annual Cycles ◽  
Funka Bay ◽  
Size At Sexual Maturity ◽  
Organ Sizes

The reproductive cycle and size at sexual maturity of the commercial whelk Buccinum isaotakii in Funka Bay, southern Hokkaido, Japan, was examined using monthly samples of individuals collected from May 1999 until October 2000. Female and male sexual maturity was determined based on reproductive organ sizes and histological examination, and sex ratios did not differ from parity. There were parallel annual cycles in the size of the ovary and pallial oviduct, and an inverse cycle for the digestive gland. The testis and seminal vesicle showed inverse cycles. The peak in seminal vesicle size was at the same time as the peak in ovary and pallial oviduct. The size of the male digestive gland exhibited no evident cycle. Males were mature from May to October 1999 and from April to October 2000, and spent individuals first appeared in September 1999 and then decreased in numbers until June 2000. Sperm content and epithelium in seminal vesicle indicated that the copulating period started in March and lasted until August 2000. Ovarian maturation and oogenesis occurred from October 1999 onwards and peaked in January 2000, with egg laying occurring from May until September. An increase in temperature coincided with the advancement of spermatogenesis and the egg laying while the transfer of the sperm from the testis to the seminal vesicle in males and the maturation of ovaries in females coincided with a decrease in temperature.

Reproductive cycle of the sea urchin Paracentrotus lividus in the Cantabrian Sea (northern Spain): environmental effects

2009 ◽  
Vol 90 (4) ◽  
pp. 699-709 ◽  
Author(s):  
J.M. González-Irusta ◽  
F. Goñi de Cerio ◽  
J.C. Canteras
Keyword(s):  
Sea Urchin ◽  
Reproductive Cycle ◽  
Phytoplankton Bloom ◽  
Chlorophyll Concentration ◽  
Gonad Index ◽  
Paracentrotus Lividus ◽  
Northern Spain ◽  
Spring Phytoplankton Bloom ◽  
In The Beginning ◽  
Spawning Periods

The main objective of this study was to describe the reproductive cycle of the sea urchin Paracentrotus lividus on the Cantabrian coast (north of Spain), and assess its relationship with environmental factors. To achieve this, samples were taken monthly from three localities during 17 months in two different habitats. At least 15 individuals from each location and habitat were collected during each sampling occasion and used for assessments of gonad index and histological sections. The water temperature and the chlorophyll concentration were also measured. The breeding season of P. lividus in Cantabria started in March and continued until September with one or two main spawning periods per year (depending on year and population), the first one in the beginning of spring and the second one in the summer. The most important differences in the gonad cycle were observed among localities, and the smallest among habitats. Temperature, photoperiod and nutritive stage are important factors controlling the gonad cycle. The beginning of spawning in the Cantabrian populations coincides with the spring phytoplankton bloom and the rise in temperature, which may act as environmental triggers.

Reproductive biology of the commercial sea cucumber Athyonidium chilensis (Holothuroidea: Dendrochirotida) in southern Chile

2016 ◽  
Vol 98 (2) ◽  
pp. 311-323 ◽  
Author(s):  
Josefina Peters-Didier ◽  
Luis Miguel Pardo ◽  
Orlando Garrido ◽  
Carlos S. Gallardo
Keyword(s):  
Sexual Maturity ◽  
Sea Cucumber ◽  
Fishery Management ◽  
Gonad Index ◽  
Microscopic Analysis ◽  
Relevant Information ◽  
Southern Chile ◽  
Spawning Activity ◽  
High Fecundity ◽  
Sexually Mature

Reproductive aspects of the sea cucumber Athyonidium chilensis were studied over a year in Valdivia, Chile, through gonad index (GI) analysis, macro- and microscopic analysis of the gonads, fecundity and size at first sexual maturity estimations. We also explored the reliability of live size estimators for their use in fisheries. Athyonidium chilensis showed continuous gametogenesis and spawning individuals could be found throughout the year. However, spring was the main reproductive time, where an important GI decrease coincided with enhanced spawning activity evidenced through histology. GIs recovered in summer, and new signs of enhanced spawning activity were observed towards autumn (April 2008). GI peaks were observed in August 2007 and March 2008 for females (22.8 and 24.4% respectively) and September 2007 and March 2008 for males (31.9 and 25.9% respectively). Low mean GIs occurred in May and December 2007 for females (15.2 and 11.6% respectively) and May and October 2007 for males (12.7 and 14.1% respectively). Males reached sexual maturity at a smaller size than females (males: 21.2 g, females: 43.7 g eviscerated weight), and mature females showed a high mean absolute fecundity for a species with lecithotrophic larval development (6.31 × 105 ± 1.97 × 105 SD). For fisheries, we recommend a minimum catch size over 237.89 g drained weight to ensure that caught individuals are sexually mature. This study provides relevant information for the conservation and fishery management of A. chilensis. Continuous gametogenesis and high fecundity make this species particularly suitable for aquaculture in southern Chile.

scholarly journals Some biological characteristics of the Far Eastern sea cucumber (Apostichopus japonicus) from the Severnaya Bay of the Slavyanka Gulf (Japan Sea)

2021 ◽  
pp. 63-68
Author(s):  
I. V. Matrosova ◽  
A. A. Politayeva
Keyword(s):  
Sex Ratio ◽  
Body Length ◽  
Sea Cucumber ◽  
Apostichopus Japonicus ◽  
Gonad Index ◽  
Japan Sea ◽  
Biological Characteristics ◽  
Biological Traits ◽  
Far Eastern

Some of biological traits of the Far Eastern sea cucumber from the Severnaya Bay were examined in 2016 and 2017. Body length of sea cucumber individuals varied from 3.6 to 23.4 cm. Dermo-muscular bag weight was higher in 2017 (137.5 g). Individual ages were 1–4 years in 2016 and 1–5 years in 2017. Sex ratio was near 1:1 in 2016 and 2017. During the period of the research gonad index was maximal in June – 10.6%. Spawning began in the 2nd decade of June and finished in the 2nd decade of July.

scholarly journals Population biology of Uca mordax (Smith, 1870) (Crustacea, Decapoda, Ocypodidae) from the southeastern coast of Brazil

2009 ◽  
Vol 31 (73/75) ◽  
Author(s):  
Vivian Fransozo ◽  
Rafael Campanelli Mortari ◽  
Aline Staskowian Benetti
Keyword(s):  
Sex Ratio ◽  
Population Biology ◽  
Sexual Maturity ◽  
Fiddler Crab ◽  
Carapace Width ◽  
Southeastern Coast ◽  
Size Classes ◽  
Median Size ◽  
Size At Sexual Maturity ◽  
Males And Females

The population biology of the fiddler crab Uca mordax (Smith, 1870) was investigated in an estuarinemangrove from the southeastern coast of Brazil. Samplings were monthly performed by 2 collectors for30 min. using the technique of capture per unit effort during low tide periods. The allometric techniquewas used to determine crab size at sexual maturity (males and females). Thus, specimens were classified into juveniles and adults according to their size at sexual maturity for each sex. The specimens weredistributed into size classes. Recruitment was based on the juvenile frequency and the reproduction peakin ovigerous females. The median size of males was 15.9 ± 2.7 mm carapace width (CW) (n = 557) andthat of females, 14.6 ± 2.8 mm CW (n = 528). At sexual maturity, size of crabs was 11.9 mm CW formales and 11.5 mm CW for females. Juveniles were found throughout the year but more frequently inthe winter and autumn. Sex ratio did not differ among seasons, except during the summer (p < 0.05).As regards sex ratio per size class, females predominated in the fi rst size classes. Reproduction peakwas observed in the summer. In short, the population biology of U. mordax was similar to that of mostbroad-front fi ddler crab species.

Some Reproductive Aspects of Latreutes Fucorum (Fabricius, 1798) (Decapoda, Hippolytidae) from Bahía De La Ascensión, Quintana Roo, Mexico

Crustaceana ◽  
2011 ◽  
Vol 84 (11) ◽  
pp. 1353-1365 ◽  
Author(s):  
Mario Martínez-Mayén ◽  
Ramiro Román-Contreras
Keyword(s):  
Sex Ratio ◽  
Sexual Maturity ◽  
Atlantic Coast ◽  
Quintana Roo ◽  
Egg Volume ◽  
Reproductive Characteristics ◽  
Stage Of Development ◽  
Average Fecundity ◽  
Size At Sexual Maturity ◽  
Size Interval

Abstract Latreutes fucorum (Fabricius, 1798) has a distribution that includes the American Atlantic coast from Canada to Brazil and part of the Antilles, as well as the Azores Islands and Cape Verde in the eastern Atlantic; however, there is little published information on the reproduction of this species. The aim of this study is to provide data on some reproductive characteristics of L. fucorum as fecundity, egg volume, sex ratio, and size at sexual maturity (CL50). The shrimps were collected on Thalassia testudinum Banks & Solander ex König meadows in Bahía de la Ascensión, Quintana Roo, Mexico during May 2002 by means of a Coleman-Seagrove sledge net with 800 μm mesh opening. We analysed 1097 specimens, from which was obtained a sex ratio of 1.59 males per female. The size interval of ovigerous females was 1.80 to 3.88 mm cephalothoracic length (CL), and we estimated a size at sexual maturity in the population of 2.55 ± 0.79 mm CL. Average fecundity was 96.25 ± 53.16, with 25 eggs as minimum and a maximum of 323, with a correlation coefficient of 0.72 between cephalothorax length and fecundity. Average egg volume varied from 0.013 mm3 in the first stage of development to 0.025 mm3 in embryos near hatching, which represents an increase of 92.3%. This is the first study about reproductive characteristics of L. fucorum for the Atlantic coast of Mexico.

The spiny lobster, Jasus lalandei (H. Milne-Edwards), in South Australia. II. Reproduction

1964 ◽  
Vol 15 (2) ◽  
pp. 133 ◽  
Author(s):  
DR Fielder
Keyword(s):  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Spiny Lobster ◽  
South Australia ◽  
Indirect Evidence ◽  
Ovarian Cycle ◽  
Microscopic Structure ◽  
Stages Of Development ◽  
Size At Sexual Maturity ◽  
Female Reproductive Cycle

The female reproductive cycle is described in detail. The ovarian cycle passes through seven stages of maturation, recognized by changes in macroscopic and microscopic structure. The presence of ovigerous setae in females has been used to estimate size at sexual maturity; these setae are developed fully only at the maturity moult. No stages of development could be described for the testis from macroscopic or microscopic examinations. The structure of the testis and the process of spermatogenesis are described and compared with results obtained by Matthews (1951) for Panulirus pencillatus (Oliver). No simple indication of sexual maturity was found for males, but an estimate was made using other, indirect, evidence.

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