Reproductive cycle of the mangrove oyster, Crassostrea rhizophorae (Bivalvia: Ostreidae) cultured in a macrotidal high-salinity zone on the Amazon mangrove coast of Brazil

ABSTRACT This study aimed to establish the reproductive cycle of the mangrove oyster, Crassostrea rhizophorae cultured in the macrotidal estuary of the Paciência River, Maranhão state, on the northeastern coast of Brazil, and its relationship with environmental factors. Oysters were collected monthly throughout 2013 for histological analysis of sex ratio, gonadal development and condition index. The sex ratio was 1:1.39 (M:F) and only 5 specimens presented hermaphroditism. The breeding process was continuous throughout the year and mature (IIIA stage) and spawning oysters (IIIB stage) were present in practically all months. Low variation in temperature seemed to be the main factor for the continuity of the reproductive cycle. Besides temperature, the relationship between rainfall, salinity and primary productivity affected the stimulus and timing of reproductive events. The rainy season, with low values of salinity and high values of chlorophyll a and particulate organic matter, appeared to be the main reproductive period, with release of gametes and production and maturation of new gamete cohorts in the short term. In the tropics, where gamete maturation and release seem to be continuous and concomitant, the condition index does not appear to be the best method to assess reserve accumulation peaks and gonadal repletion.

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Reproductive cycle and gonadal development of Donax striatus (Bivalvia: Donacidae) on an Amazon sandy beach in northern Brazil

Scientia Marina ◽

10.3989/scimar.04823.15a ◽

2019 ◽

Vol 83 (1) ◽

pp. 31

Author(s):

Ewertton Gadelha ◽

Elton Silva ◽

Rosana Silva ◽

Shirley Rafael ◽

Fábio Pamplona ◽

...

Keyword(s):

Organic Matter ◽

Reproductive Cycle ◽

Sandy Beach ◽

Condition Index ◽

Gonadal Development ◽

Reproductive Period ◽

Tropical Environments ◽

Northern Brazil ◽

First Maturity ◽

Size At First Maturity

The reproductive cycle and gonadal development of Donax striatus from a sandy beach in Ajuruteua, Amazon region, were studied. Monthly sampling took place from March 2015 to April 2016. Histological analysis was performed on 420 individuals, and the oocyte diameters were determined from histological sections and used to determine the reproductive period. The population showed a balanced sex ratio (1:1) with a size at first maturity of 10.9 mm in males and 8.9 mm in females. The population showed r-strategist characteristics and continuous spawning, and the reproductive cycle showed no seasonal variation or significant relation with any environmental parameter. The organic matter was significantly higher in the rainy season. According to the generalized linear model analysis (GLM), only the condition index (CI) had a significant relationship with the organic matter of the sediment. The type of reproductive strategy adopted by D. striatus corroborates the global breeding hypotheses for species of tropical environments. For conservation, it should be recommended to harvest this species at a shell length above 13 mm.

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Population structure and reproductive behavior of Sinaloa cichlid Cichlasoma beani (Jordan, 1889) in a tropical reservoir

Neotropical Ichthyology ◽

10.1590/s1679-62252011005000035 ◽

2011 ◽

Vol 9 (3) ◽

pp. 593-599 ◽

Cited By ~ 2

Author(s):

Melgen A. García-Lizárraga ◽

Francisco Enrique Soto-Franco ◽

Javier Marcial de Jesús Ruiz Velazco-Arce ◽

José Iván Velázquez-Abunader ◽

Jorge Saúl Ramírez-Pérez ◽

...

Keyword(s):

Population Structure ◽

Sex Ratio ◽

Multinomial Distribution ◽

Mesh Size ◽

Condition Index ◽

Reproductive Period ◽

Tropical Reservoir ◽

Timing Of Reproduction ◽

First Maturity ◽

Size At First Maturity

The population structure and reproductive condition of the Sinaloa cichlid Cichlasoma beani from samples obtained from June 2000 to July 2001 were determined. Samples in the first week each month from the largest trader of tilapia in the Aguamilpa Reservoir in Mexico and were caught in gillnets (9.6 and 11.4 cm stretch-mesh size). Of 596 specimens, there were 427 males and 169 females; monthly sex ratio, frequency of lengths by the multinomial distribution, timing of reproduction, condition index, and size at first maturity was determined. Differences in the sex ratio and monthly totals were significant, favoring males, except for September 2000 and March 2001. From one (August 2000) to three modal groups (July 2000 and June 2001) were identified by size. There were no significant differences in standard length weight relationships by sex, which indicated that a shared model for both genders is appropriate, and isometric growth was detected. Based on the proportion of mature and partially matures fish, the main reproductive period was April through June; size at first maturity was 18.9 cm. Water temperature was not significantly related to the percentage of mature and partially matures Sinaloa cichlids or spawning. These findings provide information for regulating the Cichlasoma beani fishery in this region such minimum legal size and non-fishing period.

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Seasonal variation in thyroid activity of turtle Lissemys punctata with respect to annual cycle of reproduction

Journal of Applied and Natural Science ◽

10.31018/jans.v2i2.119 ◽

2010 ◽

Vol 2 (2) ◽

pp. 194-199

Author(s):

Vidya R. Chandavar ◽

Prakash R. Naik

Keyword(s):

Seasonal Variation ◽

Reproductive Cycle ◽

Annual Cycle ◽

Seasonal Cycle ◽

Maximum Size ◽

Reproductive Period ◽

Thyroid Activity ◽

The Relationship

The objective of the present investigation was to study the relationship between thyroid activity and reproductive cycle in turtle Lissemys punctata. The animals were studied in the annual seasonal cycle of reproduction for two consecutive years, which is distinguished into three separate periods namely regenerative, reproductive and recrudescent. The thyroid in L. punctata was observed to be a single pyramid shaped gland, creamy white to reddish-brown in color with lenticular profile. The diameter of the follicle was lowest in regenerative period, whichgradually increased in reproductive period attaining maximum size in recrudescent, where as epithelial height was highest in regenerative period, which gradually decreased in reproductive period reaching minimum in recrudescent period. Thyroid activity varies annually in relation to different phases of reproductive periods.

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Reproductive cycle and sperm storage of female coral snakes, Micrurus corallinus and Micrurus frontalis

Amphibia-Reptilia ◽

10.1163/15685381-20191189 ◽

2020 ◽

Vol 41 (1) ◽

pp. 13-27 ◽

Cited By ~ 1

Author(s):

Erick Augusto Bassi ◽

Rafaela Zani Coeti ◽

Selma Maria de Almeida-Santos

Keyword(s):

Reproductive Cycle ◽

Sperm Storage ◽

Reproductive Period ◽

Long Term Storage ◽

Ovulatory Period ◽

Reproductive Cycles ◽

Reproductive Events ◽

Autumn And Winter ◽

First Time

Abstract We analyzed the hypothesis that the lack of synchronization between the mating and ovulation period of Micrurus frontalis (BRT clade) is indicative of the capacity of females to store sperm. Conversely, since these reproductive events occur in the same season for Micrurus corallinus (BRM clade), sperm storage is not expected. Thus, we analyzed the reproductive cycle of female M. corallinus and M. frontalis, and investigated the occurrence of sperm storage. Our results showed that these two species of coral snakes (clades BRM and BRT) possess different reproductive cycles. Micrurus frontalis exhibits an extensive reproductive period encompassing three seasons (summer, autumn and winter), while M. corallinus directs secondary vitellogenesis and ovulation to the hottest period of the year (spring and summer). We confirm, for the first time, the strategy of sperm storage (SSr) in females of the genus Micrurus. We observed sperm storage receptacles located in the non-glandular uterus in all seasons of the year for M. corallinus and in spring, summer and autumn in M. frontalis. Furthermore, the presence of SSr in females in the non-reproductive (post-ovulatory) period, the verification of myoid cells around the receptacles and secretion of neutral carbohydrates in the lumina of SSrs may indicates a long-term storage. The posterior infundibulum is another possible region of sperm storage by the presence of tubular ciliated gland; however, reproductive studies with other species of the genus are necessary for a better understanding of the reproductive strategies of the BRT and BRM clades.

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Reproductive cycle of native viviparous fish species (Actinopterygii: Cyprinodontiformes: Goodeidae) in a subtropical Mexican lake

Neotropical Ichthyology ◽

10.1590/1982-0224-2021-0105 ◽

2021 ◽

Vol 19 (4) ◽

Author(s):

Arely Ramírez-García ◽

Rodrigo Moncayo-Estrada ◽

Juan José González-Cárdenas ◽

Omar Domínguez-Domínguez

Keyword(s):

Sex Ratio ◽

Reproductive Cycle ◽

Fish Species ◽

Gonadosomatic Index ◽

Reproductive Period ◽

High Fertility ◽

Reproductive Tactics ◽

Subtropical Lake ◽

Viviparous Fish ◽

First Maturity

Abstract Reproductive tactics and strategies contribute to the persistence and maintenance of long-term populations in fish species. Members of the subfamily Goodeinae are a group of small-bodied freshwater fish with specialized reproduction (viviparity-matrotrophy). They are found in the highlands of central Mexico, most of them endemic. The aim of this study was to conduct a comprehensive investigation to evaluate the annual reproductive cycle of seven species of goodeines (splitfins). We carried out our study in the subtropical Lake Zacapu, Mexico, with bi-monthly sampling from May 2019 to March 2020. We obtain the fertility, size at first maturity (L50), sex ratio, and gonadosomatic index. Our result shows that populations of goodeines have high fertility compared to other populations of the same species in other aquatic systems and also to other species of goodein. We found that males mature at smaller sizes than females, the observed proportion of females was greater than males in all the goodeines. Lake Zacapu goodeines have two reproductive peaks, one in spring (April to June) and another in fall (September to November). These tactics (fertility rates, sex ratio, reproductive period) and strategies (viviparity-matrotrophy) favor reproductive success in this environmentally stable subtropical lake in the highlands of Mexico.

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Growth and Sex Ratio of Octopus Paroctopus Digueti (Perrier & Rochebrune, 1894) in a Wild Population

Croatian Journal of Fisheries ◽

10.2478/cjf-2020-0006 ◽

2020 ◽

Vol 78 (2) ◽

pp. 53-68

Author(s):

Salvador Granados-Alcantar ◽

Ruth Escamilla-Montes ◽

Genaro Diarte-Plata ◽

Jesús A. Fierro-Coronado

Keyword(s):

Sex Ratio ◽

Growth Curve ◽

Growth Parameters ◽

Condition Index ◽

Total Weight ◽

Type Model ◽

Growth Equation ◽

Linear Type ◽

Weight Growth ◽

The Relationship

AbstractIn Mexico, studies of octopus Paroctopus digueti are scarce, thus the objective of this research is to evaluate some of its biological aspects in Ohuira Bay, Ahome, Sinaloa, Mexico. From autumn 2016 to autumn 2017, a total of 217 organisms of P. digueti were collected, from which 166 were females, 31 ovigerous females and 20 males. The lengths of the mantle (ML), tentacles or arms (AL) and total length (TL) were recorded as well as the total weight (TW) of each organism. The software FiSAT II was used to obtain the growth parameters by mediating seasonal size frequencies. Considering both sexes, the average registered mantle length was 40.31±2.5 mm. For the analysis of ML-TL y ML-AL, the data were adjusted to a linear-type model. For the relationship between ML-TL, the minimum determination coefficient was observed during spring R2 = 0.335, and the highest was registered in winter R2 = 0.6452. With regards to the allometry coefficient (b), it was different among the 4 climatic seasons. The theoretical ML growth curve showed both sexes of ML∞= 73.50 mm, K = 1.30 year−1 and t0= 0.10. The estimated values from the growth equation revealed faster growth (ML∞= 63 mm) within the 1.2 years of their lives, reaching a maximum length at 2.5 years of age. The total weight growth curve of P. digueti octopus was formed by an exponential first stage up to six months and the second logarithmic stage from seven months to approximately 1.8 years. In the summer there were slightly lower coefficients and percentages of instantaneous growth coefficients (IGC) for the lengths and total weight of octopus P. digueti. The highest Fulton’s condition index (k) was recorded in winter. The sex ratio was significant in a proportion of 9.85 F:1 M.

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Gametogenesis and spawning in the subtidal white clam Spisula solida, in relation to temperature

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315498000927 ◽

1999 ◽

Vol 79 (4) ◽

pp. 753-755 ◽

Cited By ~ 15

Author(s):

M.B. Gaspar ◽

C.C. Monteiro

Keyword(s):

Sex Ratio ◽

Seawater Temperature ◽

Condition Index ◽

Gonadal Development ◽

First Year ◽

Southern Portugal ◽

Males And Females ◽

A Site ◽

First Year Of Life ◽

Definite Temperature

Seasonal variations in reproductive cycle of Spisula solida were studied between June 1995 and June 1996 at a site off Vilamoura, southern Portugal. Sex ratio was found to be in favour of males. Both males and females showed a synchronism in gonadal development and spawning. Gametogenic activity started with decreasing temperature at the beginning of autumn. The onset of spawning took place in February when the seawater temperature began to increase. Spawning ended in May. It is possible that the white clam does not spawn at a definite temperature, rather responding to the increase in seawater temperature. Between June and September, the specimens were found to be in the resting stage and the condition index increased, probably due to the accumulation of reserves. Spisula solida reached maturity during the first year of life.

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Reproductive biology of a population of Gymnotus aff.carapo (Teleostei: Gymnotidae) from southern Brazil

Neotropical Ichthyology ◽

10.1590/s1679-62252006000300005 ◽

2006 ◽

Vol 4 (3) ◽

pp. 339-348 ◽

Cited By ~ 15

Author(s):

Diego de Paula Cognato ◽

Clarice Bernhardt Fialho

Keyword(s):

Sex Ratio ◽

Dissolved Oxygen ◽

Abiotic Factors ◽

Gonadal Development ◽

Reproductive Period ◽

Size Distributions ◽

Water Conductivity ◽

Multiple Spawning ◽

Absolute Fecundity ◽

The Mean

The reproductive period and its relation with somatic and abiotic factors, the relative and absolute fecundity, spawning type, length of first maturation and sex ratio is describe for Gymnotus aff.carapo from a small lake at Itapuã State Park, Rio Grande do Sul, Brazil. Gymnotus aff. carapo presents a relatively long reproductive cycle extending from November/2003 to March/2004. Decreases in water conductivity and increases in dissolved oxygen are correlated with increased gonadal development in males. In females, seasonal increases in temperature and photoperiod and decreases in dissolved oxygen are correlated with increased gonadal development. The mean absolute fecundity was 915.3 oocytes, and mean relative fecundity 0.20 oocytes/mg body weight. Egg size distributions indicate multiple spawning. The size of first maturation was 141 mm in females and 146 mm in males. The sex ratio was 1:1, with a male bias only in smaller size classes.

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Fecundity and Gonado-somatic Index of Trichiurus lepturus (Linnaeus, 1758) Along the Zamboanga del Norte Coast

International Journal of Emerging Research in Management and Technology ◽

10.23956/ijermt.v6i7.196 ◽

2018 ◽

Vol 6 (7) ◽

pp. 120

Author(s):

Ma. Dulce C. Guillena

Keyword(s):

Sex Ratio ◽

Stock Assessment ◽

Chi Square ◽

Moon Phases ◽

Ovary Weight ◽

Moment Coefficient ◽

Trichiurus Lepturus ◽

Significant Difference ◽

The Relationship ◽

Somatic Index

Gonado-somatic index and fecundity are tools for measuring the sexual maturity and ability of animals to reproduce. This study investigates the reproduction of Trichiurus lepturus. Specifically, this aimed to determine the sex ratio, the GSI, the relationship between fecundity and total length, fecundity and total weight, fecundity and ovary weight. The Descriptive Method of research was used. Percentage and chi-square was utilized in determining the percentage of occurrence and sex ratio respectively. Pearson r Product Moment Coefficient of Correlation was used to determine the relationships of the parameters. The study revealed that females outnumbered males and the sex ratio for different month showed significant difference. Spawning season was observed to occur in November and December as revealed in its GSI values and it synchronized with the full and new moon phases. Fecundity is positively correlated with body weight, body size, and ovary weight where ovary weight is observed to be the best index for fecundity. The results of this study could be used further for formal stock assessment of cutlassfish fishery.

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Proliferative and Apoptotic Pathways in the Testis of Quail Coturnix coturnix during the Seasonal Reproductive Cycle

Animals ◽

10.3390/ani11061729 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1729

Author(s):

Sara Falvo ◽

Luigi Rosati ◽

Maria Maddalena Di Fiore ◽

Federica Di Giacomo Russo ◽

Gabriella Chieffi Baccari ◽

...

Keyword(s):

Reproductive Cycle ◽

Second Messengers ◽

Reproductive Period ◽

Annual Reproductive Cycle ◽

Coturnix Coturnix ◽

Immunohistochemistry Analysis ◽

17Β Estradiol ◽

Apoptotic Pathways ◽

Camp And Cgmp ◽

Activation Phase

The quail Coturnix coturnix is a seasonal breeding species, with the annual reproductive cycle of its testes comprising an activation phase and a regression phase. Our previous results have proven that the testicular levels of both 17β-estradiol (E2) and androgens are higher during the reproductive period compared to the non-reproductive period, which led us to hypothesize that estrogens and androgens may act synergistically to initiate spermatogenesis. The present study was, therefore, aimed to investigate the estrogen responsive system in quail testis in relation to the reproduction seasonality, with a focus on the molecular pathways elicited in both active and regressive quail testes. Western blotting and immunohistochemistry analysis revealed that the expression of ERα, which is the predominant form of estrogen receptors in quail testis, was correlated with E2 concentration, suggesting that increased levels of E2-induced ERα could play a key role in the resumption of spermatogenesis during the reproductive period, when both PCNA and SYCP3, the mitotic and meiotic markers, respectively, were also increased. In the reproductive period we also found the activation of the ERK1/2 and Akt-1 kinase pathways and an increase in second messengers cAMP and cGMP levels. In the non-reproductive phase, when the E2/ERα levels were low, the inactivation of ERK1/2 and Akt-1 pathways favored apoptotic events due to an increase in the levels of Bax and cytochrome C, with a consequent regression of the gonad.

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