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

Author(s):  
Josefina Peters-Didier ◽  
Luis Miguel Pardo ◽  
Orlando Garrido ◽  
Carlos S. Gallardo

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.

2018 ◽  
Vol 66 (4) ◽  
Author(s):  
Arlenie Rogers ◽  
Jean-François Hamel ◽  
Annie Mercier

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. 


1976 ◽  
Vol 54 (2) ◽  
pp. 156-161 ◽  
Author(s):  
C. L. Glenn ◽  
R. R. G. Williams

Age at sexual maturity, seasonal gonadal development, and fecundity estimates of mooneye were determined from 695 samples captured in the Assiniboine River between November 17, 1972, and November 2, 1973. Most mooneye became sexually mature in their 4th (III +) or 5th (IV +) year of life, with more males mature at age III + than females. During 1973, spawning began after May 8 and was completed by June 12. The peak spawning activity occurred during mid-May when water temperatures ranged from 10 to 13 °C. All age groups of sexually mature females had rapid ovarian development during the summer months with about 80% of maximum ovarian weight present by October 17. Ripe ova have a mean diameter of 1.98 ± 0.07 mm. The mean annual total fecundity of Assiniboine River mooneye was about 5000–9000 ova per female. The mean annual relative fecundity was about 2000–2400 ova per 100 g body weight.


1979 ◽  
Vol 13 (3) ◽  
pp. 283-286 ◽  
Author(s):  
M. L. Norris ◽  
C. E. Adams

Summary Keeping a sexually mature male with a weanling female rat advanced neither the time of vaginal opening nor that of 1st oestrus. In 2 of 3 experiments females kept singly after weaning reached sexual maturity significantly earlier than did grouped females. The reproductive performance of females mated at 1st oestrus was not significantly different from that of older primiparae. 26 rats gave birth to an average of 9·3 young at 59·5 days of age, and 22 of them reared 96% of the young to weaning.


Author(s):  
Gil G. Rosenthal

This chapter focuses on social interactions, in the broadest sense, as sources of variation in mate choice and mating preferences. These interactions can be divided into three categories corresponding to when they are specified and which individuals are involved. The first includes effects that are determined before birth and transmitted vertically from parents: epigenetic modifications to the genome and the fetal or embryonic environment. The second includes influences between birth and sexual maturity, when the phenotypes of parents and/or other sexually mature, older individuals (oblique transmission) direct the development of preferences in choosers. Experience with courters and choosers after sexual maturity, or experience with other juveniles that shapes subsequent preferences, constitutes peer (horizontal) transmission.


2020 ◽  
Vol 223 (23) ◽  
pp. jeb232496 ◽  
Author(s):  
Francois Criscuolo ◽  
Roxanna Torres ◽  
Sandrine Zahn ◽  
Tony D. Williams

ABSTRACTAvian eggs contain a large number of molecules deposited by the mother that provide the embryo with energy but also potentially influence its development via the effects of maternally derived hormones and antibodies: the avian egg is thus ‘multivariate’. Multivariate effects on offspring phenotype were evaluated in a study on captive zebra finches, by simultaneously manipulating maternally derived antibodies (MAb) by lipopolysaccharide (LPS) treatment of mothers and injection of testosterone into the egg yolk. LPS treatment had a positive effect on body mass growth at 30 days after hatching and immune response at sexual maturity, while egg testosterone treatment positively influenced immune response at fledging and courtship behaviour in sexually mature male offspring. Maternal effects are known to modulate offspring telomere length (TL). However, the multivariate effects of egg-derived maternal components on offspring telomere dynamics from hatching to sexual maturity are undefined. Here, we tested: (1) the effects of LPS and testosterone treatments on TL from hatching to sexual maturity (day 82); (2) how LPS treatment modulated TL over reproduction in adult females; and (3) the relationship between maternal and offspring TL. We predicted that TL would be shorter in LPS fledglings (as a cost of faster growth) and that TL would be longer in sexually mature adults after yolk testosterone treatment (as a proxy of individual quality). In adult females, there was an overall negative relationship between laying and rearing investments and TL, this relationship was weaker in LPS-treated females. In chicks, there was an overall negative effect of LPS treatment on TL measured at fledging and sexual maturity (day 25–82). In addition, at fledging, there was a Sex×LPS×Testosterone interaction, suggesting the existence of antagonistic effects of our treatments. Our data partially support the hypothesis that telomeres are proxies of individual quality and that individual differences in TL are established very early in life.


2019 ◽  
Vol 6 (3) ◽  
pp. 181700 ◽  
Author(s):  
Katrin Pretterebner ◽  
Luis Miguel Pardo ◽  
Kurt Paschke

Male-biased fishery management can provoke depletion of seminal reserves, which is the primary cause of sperm limitation. Therefore, identifying factors which contribute to the vulnerability to depletion of seminal reserves is a priority. The present study aimed to determine the effect of temperature on the recovery rate of sperm and seminal reserves after their depletion in Lithodes santolla , an important fishery resource in southern Chile. Sperm and seminal reserves were not fully recovered within 30 days. Temperature significantly affected seminal recovery: after 30 days the recovery index increased to 40% and 21% at 9°C and 12°C, respectively. The twice as fast seminal recovery at 9°C may be explained by the zone of origin of the individuals in this study (northern distributional limit), and 12°C may be close to the threshold of temperature tolerance. Lithodes santolla populations subject to intense male-only fisheries may be vulnerable to depletion of seminal reserves and a climate change scenario could additionally aggravate the risk of seminal depletion in L. santolla in its northern distributional limit.


2017 ◽  
Vol 95 (7) ◽  
pp. 473-483 ◽  
Author(s):  
Ximena González-Pisani ◽  
Pedro J. Barón ◽  
Laura S. López Greco

An integrative analysis of sexual maturity associated with growth was developed for the spider crab Leurocyclus tuberculosus (H. Milne Edwards and Lucas, 1842). Sexual maturity was characterized based on gonadal, morphological, morphometric, and functional sexual maturity. Progress in sexual maturation was described through 13 growth stages (instars) detected by the examination of size (carapace width) frequency distributions. Mature females displayed mature ovaries, developed vaginae, open gonopores, allometric changes in the abdomen, and ovigerous stage in the transition from instar IX to instar X. Sexually mature males presented spermatophores in the distal vasa deferentia and allometric changes in several measurements of the right chela in the transition from instar X to instar XI. However, two prepubertal phases were recognized in both sexes separated from each other by a prepubertal critical molt. Preceding the second critical molt, gonopores were sealed and vasa deferentia showed no spermatophores, and therefore neither sex was able to mate. The integrated analysis of size at maturity and size frequency distributions showed that in both sexes molt to gonadal, morphological, morphometric, and functional sexual maturity occurred in advance of the terminal molt, in contrast with patterns observed in other Majoidea.


2009 ◽  
Vol 81 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Eduardo J.B. Lima ◽  
Paula B. Gomes ◽  
José R.B. Souza

The edible sea urchin Echinometra lucunter (Linnaeus, 1758) is a very common species on the sublittoral-midlittoral in Brazilian rocky shores. The aim of this work was to describe the gametogenesis and reproductive strategy of the E. lucunter population at Muro Alto beach in the Northeast coast of Brazil from August 2004 to August 2005. A total of 240 specimens were collected on the sandstone reef flat from a tidepool during spring low tides. The overall sex ratio was1.12:1,withoutsignificanttemporalvariationexceptinOctober2004. Firsts sexual maturity ocurred in individuals from a diameter of 20.8 mm. There was not a significant difference in gonad index between females and males during the sampling period. The female's gonad index variation was associated with a well-defined spawning, corroborated by the histological analysis of the gonads, which demonstrates sex differences of the gamete production. By contrast, the males showed no clear pattern. It is suggested that continuous reproduction with seasonal peaks in the E. lucunter population occurs at Muro Alto beach.


1967 ◽  
Vol 45 (6) ◽  
pp. 979-989 ◽  
Author(s):  
H. J. Duncan ◽  
R. H. Common

The value of the quotient, 14CO2 liberated from glucose-1-14C over 14CO2 liberated from glucose-6-14C, for chicken liver slices has been determined. It did not deviate appreciably from unity for slices from (a) immature and sexually mature females, (b) a group of females at intervals during their transition from sexual immaturity to sexual maturity, (c) immature males, and (d) immature females treated by injection with estradiol monobenzoate. Incubation of the liver slices under anaerobic conditions reduced CO2 liberation to very low values and approximately doubled the quotient. Incubation in the presence of arsenite reduced oxidation but increased the quotient about fourfold. Incubation under anaerobic and aerobic conditions, with addition of pyruvate, increased the quotient value.It is concluded that the phosphogluconate-oxidative pathway, if active at all in chicken liver, plays a subordinate role in carbohydrate metabolism in this tissue compared with its role in carbohydrate metabolism in rat liver.


Parasitology ◽  
1967 ◽  
Vol 57 (1) ◽  
pp. 157-167 ◽  
Author(s):  
G. C. Kearn

Acanthocotylid (monogenean) parasites inhabit the skin of rays, and the lack of cilia on the infective larvae of these parasites may be an adaptation to the host's bottom-living habits.Freshly hatched larvae must remain on the sea-bottom until a ray settles on top of them, when the larvae then have the opportunity to attach themselves to the host's ventral surface. Acanthocotyle lobianchi, which infects Raia montagui and R. clavata at Plymouth, becomes sexually mature on the host's ventral surface and rarely wanders from it, but A. elegans, which is found on R. clavata only, migrates to the dorsal surface of the host before reaching sexual maturity.The larvae of acanthocotylids use their haptoral hooklets to attach themselves to the host's epidermis, but as the parasites increase in size the load on these hooks becomes acute. This load is relieved not as in other monogeneans by the development of hamuli but by the transformation of the posterior third of the larval body into an accessory ‘pseudohaptor’.I am obliged to the Director and Staff of the Plymouth Laboratory for laboratory facilities and to Mr J. E. Green for his interest and help on many occasions.


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