scholarly journals Fecundity of Morocco Dentex Dentex maroccanus Valenciennes, 1830 Distributed in Izmir Bay (Central Aegean Sea of Turkey)

2018 ◽  
Vol 6 (5) ◽  
pp. 624
Author(s):  
Burcu Taylan ◽  
Bahar Bayhan ◽  
Oğulcan Heral
Keyword(s):  
Gonadosomatic Index ◽  
Aegean Sea ◽  
Reproductive Period ◽  
Male Fish ◽  
Exponential Relationship ◽  
Phase Discrimination ◽  
Total Fecundity ◽  
Fish Samples ◽  
Dentex Dentex ◽  
Discrimination Method

In this study, the reproductive properties of the Dentex maroccanus species distributed in the Aegean Sea were determined. A total of 439 fish were collected during the period from December 2012 to March 2014 from the commercial fishers who seasonally hunt in the Foça-Mordoğan region (İzmir, Turkey) were examined. After the measurement of the total lengths and body and gonad weights of the fish samples in the laboratory, their sexes were identified, which revealed that 140 of the samples were male, 206 of the samples were female and 93 of the sample were undeterminated. The female:male ratio was 1.5:1. The 5-point maturity phase discrimination method developed by Holden and Raitt for maturity stages in 1974 was macroscopically examined for female and male fish specimens. A total of 16 ovaries, which were determined to be at the 3rd and 4th stages of maturity according to the method, were used to determine fecundity. The gonadosomatic index values that were calculated based on the seasons revealed that the reproductive period of the species was summer (2.87) and autumn (2.10). The first maturation length for the species was 13.4 cm. Estimates of total fecundity varied between 74252 and 201187 eggs (mean: 123263±44586). There was an exponential relationship between fecundity and total length as F = 10.643L3.111. The diameter of the mature eggs ranged from 0.49 mm to 0.67 mm (mean: 0.59±0.06 mm).

Preliminary results on the ovarian histology of rabbitfish Siganus rivulatus (Forsskal, 1775) in the southern Aegean Sea, Turkey

2020 ◽  
Vol 49 (3) ◽  
pp. 207-214
Author(s):  
Serhat Engin ◽  
Ozan Soykan ◽  
Hasan Cerim ◽  
Anıl Gülşahin
Keyword(s):  
Gonadosomatic Index ◽  
Aegean Sea ◽  
Early Summer ◽  
Small Scale ◽  
Annual Reproductive Cycle ◽  
Histological Changes ◽  
Recreational Angling ◽  
Fish Samples ◽  
Post Spawning ◽  
Siganus Rivulatus

AbstractThe study aimed to determine the annual reproductive cycle of Siganus rivulatusfi females based on monthly variation of the gonadosomatic index (GSI) and histological changes in gonads. A total of 240 fish samples were collected monthly from small-scale (trammel nets) and recreational (angling and pot fishery) fishing from Gökova Bay, the southern Aegean Sea, between July 2017 and June 2018. The length and weight of female fish varied from 10.8 to 26.1 cm with a mean length of 18.7 ± 0.2 cm and from 14.98 to 293.42 g with a mean weight of 91.1 ± 2.93 g. GSI values began to increase in May, peaked in June and gradually decreased in July, indicating that the spawning season was early summer. A total of 240 gonads were histologically examined. Granular, pinkish structure of eggs was observed primarily between April and June, which was consistent with the increase in the gonadosomatic index. Post-spawning follicles were determined in July. Values of the gonadosomatic index gradually decreased after August and they were minimal between September and November. During this period, ovaries were surrounded by immature oocytes at the chromatin and peri-nucleolus stages. These results revealed thatSiganus rivulatusstarted vitellogenesis in April and the gonadosomatic index peaked in June.

scholarly journals Reproductive biology of Plesionika narval in the SE Aegean Sea (Eastern Mediterranean)

2017 ◽  
pp. 454 ◽  
Author(s):  
AIKATERINI ANASTASOPOULOU ◽  
PANAGIOTA MAKANTASI ◽  
KOSTAS KAPIRIS ◽  
CHRIS J. SMITH ◽  
CHRISTOS MARAVELIAS ◽  
...  
Keyword(s):  
Reproductive Biology ◽  
Carapace Length ◽  
Gonadosomatic Index ◽  
Aegean Sea ◽  
Reproductive Period ◽  
Small Scale ◽  
Female Size ◽  
Depth Range ◽  
Depth Zone ◽  
Widespread Species

Plesionika narval is a widespread species of the Pandalidae family, of particular high economic importance for small-scale shrimp trap fisheries in the Dodecanese Islands (SE Aegean Sea). Understanding its biology and reproduction are crucial for stock management. Reproductive biology aspects were studied through data collected during monthly experimental surveys with baited shrimps traps from November 2014 to October 2015 at a depth range of 10 - 150m. A total of 3436 individuals within the size range of 6.46 to 20.20 mm carapace length (CL) was analyzed. Overall, mean female size was significantly higher than mean male size, while the mean size of ovigerous females was higher than that of non-ovigerous females. Mean carapace length of ovigerous and non-ovigerous females was significantly correlated to depth. Ovigerous females were observed throughout the study period; however, monthly proportions revealed April to October as the main reproductive period of the species in the area. The sex ratio showed a clear predominance of females in the shallow depth zone (10-25 m) and was found to be affected by sampling area and depth zone. Immature females were found from November to March. Mature females were found all year round, exhibiting higher percentages in March, June, July and September, coinciding with the main reproductive period. P. narval seemed to spawn more than one time within the annual reproductive cycle. Gonadosomatic index obtained its highest mean values in May, June and September, thus revealing the main reproductive period. Size at first maturity for females was estimated at CL50=11.7 mm.

Life-history traits of the striped red mullet Mullus surmuletus (Linnaeus, 1758) in the south Aegean Sea (eastern Mediterranean)

2019 ◽  
Vol 99 (06) ◽  
pp. 1417-1427 ◽  
Author(s):  
Vasiliki Kousteni ◽  
Aikaterini Anastasopoulou ◽  
Chryssi Mytilineou
Keyword(s):  
Stock Assessment ◽  
Eastern Mediterranean ◽  
Gonadosomatic Index ◽  
Aegean Sea ◽  
Growth Function ◽  
Reproductive Period ◽  
The South ◽  
Striped Mullet ◽  
Mullus Surmuletus ◽  
Marginal Increment

AbstractAlthough the red striped mullet is one of the main target fish of the Hellenic demersal fisheries, information about its biology is limited. The aim of this study was to describe the reproductive biology and growth of the species in the south Aegean Sea based on 1032 individuals sampled under the Data Collection Framework Program in 2016. According to the monthly variation of the maturity stages and the gonadosomatic index, spawning activity took place from March to July, although it appeared to occur throughout the year. Length at 50% maturity (L50) was 153.3 and 139.2 mm in females and males, respectively. Individual ages were determined by counting the annuli of otoliths macroscopically. Marginal increment analysis (MIA) combined with complementary information derived from otolith edge analysis, the assessment of the reproductive period and the length–frequency distribution modes of the population showed that annulus formation occurs between February and April. The length–weight relationship revealed a significant sex effect and was described by the parameters α = 0.0155 and b = 2.915 in females, and α = 0.0032 and b = 2.976 in males. The von Bertalanffy growth function (VBGF) parameters for sexes combined were Linf = 346.1 mm, k = 0.299 year−1 and t0 = −0.984 years. Longevity (tmax) was estimated at 11.75 years. This study provides valuable data for the stock assessment of M. surmuletus in one of the major Hellenic fishing grounds located in the south Aegean Sea.

scholarly journals Reproductive biology of the anchovy (Stolephorus commersonnii, Lacepède, 1803) and spotted sardine (Amblygaster sirm, Walbaum, 1792) from Tanga Region, Tanzania

2021 ◽  
pp. 81-94
Author(s):  
Joseph S. Sululu ◽  
Albogast T. Kamukuru ◽  
Baraka C. Sekadende ◽  
Shigalla B. Mahongo ◽  
Mathias M. Igulu
Keyword(s):  
Reproductive Biology ◽  
Gonadosomatic Index ◽  
Northern Coast ◽  
Monthly Basis ◽  
Male And Female ◽  
Gonadal Maturity ◽  
Total Fecundity ◽  
Fish Samples ◽  
Spawning Cycle ◽  
First Maturity

The present study investigated the reproductive biology of Stolephorus commersonnii and Amblygaster sirm at two landing sites in Tanga on the northern coast of Tanzania. Fish samples were collected on a monthly basis from ringnets operated by artisanal fishers in the nearby coastal waters. Spawning seasons were determined using gonadosomatic index (GSI) and gonadal maturity stages. The size at first maturity was 57.7 mm and 66.2 mm total length for male and female S. commersonnii respectively. Male and female A. sirm were estimated to attain first maturity at 147.7 mm and 169.2 mm respectively. The spawning seasons of both species were protracted. S. commersonnii demonstrated a year round spawning cycle with peaks in August, October and January. The peak spawning season for male and female A. sirm was recorded in August and September respectively. Both species exhibited skewed size-dependent sex ratios with females predominating in the larger size classes. A. sirm had a higher fecundity rate with a maximum of 96,500 eggs in the largest female fish of 258 mm as compared to S. commersonnii (10,055 eggs) in the largest fish of 98 mm. The mean (±SE) total fecundity of S. comersonnii and A. sirm was 5,134.7 ± 136.9 eggs, and 47,029.03 ± 1,435.13 eggs in females of sizes 68 mm to 98 mm and 170 mm to 258 mm respectively.

scholarly journals Reproductive period and fecundity of Serrapinnus piaba (Characidae: Cheirodontinae) from the rio Ceará Mirim, Rio Grande do Norte, Brazil

2003 ◽  
Vol 1 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Jacira Silvano ◽  
Cristina L. C. Oliveira ◽  
Clarice B. Fialho ◽  
Hélio C. B. Gurgel
Keyword(s):  
Gonadosomatic Index ◽  
Rio Grande ◽  
Total Body Weight ◽  
Mature Female ◽  
Reproductive Period ◽  
Day Length ◽  
Maturation Stages ◽  
Total Body ◽  
Spearman Test ◽  
Test Correlation

Specimens of Serrapinnus piaba were collected monthly from April 2001 to April 2002 in the rio Ceará Mirim, Rio Grande do Norte State, Brazil. The reproductive period, determined through the monthly variation of the gonadosomatic index (GSI) and maturation stages, occurred from January to April. Non-parametric Spearman test was performed in order to test correlation of monthly GSI variation in males and females with water temperature, rainfall and day length. Rainfall and Temperature were correlated with GSI variation in females only and day length showed a negative correlation with GSI variation of males only. It was verified the presence of hooks on the anal fin of mature and maturing males along all the period of study. The absolute fecundity mean was 441 (±178.08) oocytes, determined by the number of yolky oocytes counted in 27 mature female gonads. The relative fecundity, estimated by the number of yolky oocytes divided by milligram of total body weight was 0.74 (± 0.19).

scholarly journals Invasive non-native species of fish in upper Paraná river Basin, Brazil: variations of caloric content in Cichla kelberi

2012 ◽  
Vol 10 (2) ◽  
pp. 401-408 ◽  
Author(s):  
Luis Alberto Espínola ◽  
Horácio Ferreira Júlio Junior ◽  
Evanilde Benedito
Keyword(s):  
Native Species ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Reproductive Period ◽  
Paraná River ◽  
Caloric Content ◽  
Fish Food ◽  
Gonadal Maturation ◽  
Parana River ◽  
Upper Paraná River

The allocation of assimilated energy may be influenced by seasonal changes, growth, and reproductive cycle of fish, food consumption and environmental conditions. The objective of this research was to evaluate the energetic variations of Cichla kelberi in the upper Paraná River floodplain, analyzing the caloric content in muscles, gonadosomatic index (GSI), and the condition factor between assessed systems, sex, and stage of gonadal maturation. The results obtained in the present study permit assuring that this is a species that efficiently converts the resources of the environment into energy. Although presenting higher condition factor in the environment where there is a greater ease in getting food (Paraná subsystem), the energy identified in the muscles was the same in both subsystems. During the process of gonadal maturation there is optimization in energy accumulation in the muscles of females, before and after reproductive period, and somatic growth occurs significantly when the individual is not reproducing. Further detailed studies on ecological mechanisms influencing the success of the species, as the presence of competitors and preference for native preys, are needed to implement effective management measures aimed at preventing that the species proliferation in the environment is even more damaging to local biodiversity.

scholarly journals Reproduction biology of Abe's flyingfish, Cheilopogon abei Parin, 1996 in Geser East Seram Strait Waters

2021 ◽  
Vol 21 (2) ◽  
pp. 167-184
Author(s):  
Friesland Tuapetel
Keyword(s):  
Fork Length ◽  
Biological Information ◽  
Female Fish ◽  
Male Fish ◽  
Gonad Maturity ◽  
Gill Net ◽  
Flying Fish ◽  
Reproduction Biology ◽  
Fish Samples ◽  
June July

Eco-biological information of Cheilopogon abei in Geser Streit is unknown. The objective of this research is to observe the sex ratio, first size maturity, gonad maturity and gonado somatic index (GSI) with fecundity of flying fish Ch abei in Geser East Seram Strait waters. Sampling was done for ten months started from February to November 2018, using gill net measuring 1.50 inch. All fish samples were measured in fork length and weighted so dissected to make observations on the level of gonad maturity and the number of eggs in female fish. A total of 682 flying fish was found during the study with a fork length range of 182.6-243.3 mm and a weight of 73.98-115.45 g. The results of the analysis showed that the proportion of the number of male fish was less than that of the female fish for almost every month of observation. The first size gonad mature of male and female is 210.5 mm and 214.1 mm FL. The gonad maturity index of male fish ranges from 0,963-7,967 and female fish ranges 1,315-8,069, the total fecundity is 2321-9438 eggs. Gonads of ripe fish in each month of observation. The spawning peak of Ch abei takes place in June-July and it is hoped that no arrests will be made in both months, to ensure the sustainability of the stock.

scholarly journals Reproduction of the catfish Iheringichthys labrosus (Lütken) (Pisces, Siluriformes) in Furnas reservoir, Minas Gerais, Brazil

2004 ◽  
Vol 21 (2) ◽  
pp. 193-200 ◽  
Author(s):  
José Enemir dos Santos ◽  
Nilo Bazzoli ◽  
Elizete Rizzo ◽  
Gilmar Bastos Santos
Keyword(s):  
Feeding Activity ◽  
Gonadosomatic Index ◽  
Secretory Activity ◽  
Minas Gerais ◽  
Reproductive Period ◽  
Mature Stage ◽  
Hepatosomatic Index ◽  
Gonadal Maturation ◽  
Caudal Region ◽  
Iheringichthys Labrosus

The reproductive biology of Iheringichthys labrosus (Lütken, 1874) was studied in Furnas reservoir, Minas Gerais, Brazil. The fishes, 323 males and 817 females, were captured bimonthly from August 1993 to July 1994 by using gill nets with 3-10 cm mesh size. Gonadal maturation of the specimens was analyzed through macro and microscopical characteristics of the gonads. The secretory activity of the tubules of the caudal region of the testis was analyzed during the maturational testicular cycle. Females and males were in reproductive activity throughout the year in the reservoir. The peak of advanced maturation/mature stages occurred from October to January and of spawned/spent from February to May. The spawning of I. labrosus was identified as fractional or multiple type: occurring in the reservoir or in tributaries around it. The oocyte development of the species was asynchronous as different clusters of oocytes occurred simultaneously in the ovarian parenchyma. The epithelium of the tubules of the caudal region of the testis was in high secretory activity during advanced maturation/mature stage and this activity was absence in resting. The gonadosomatic index followed gonadal maturation, and the hepatosomatic index of females was lowest in advanced maturation/mature probably due the contribution of the liver in the vitellogenesis. The variations of the stomach repletion index, coelomic fat and condition factor indicated that the feeding activity was reduced and that the energetic reserves were consumed during the reproductive period.

scholarly journals Reproductive indicators of the endemic species Astyanax bifasciatus (Teleostei: Characidae) in a tributary of the Lower Iguaçu River Basin, Brazil

2019 ◽  
Vol 41 ◽  
pp. e47720
Author(s):  
Elton Celton de Oliveira ◽  
Alexandre Augusto Auache-Filho ◽  
Denis Damasio ◽  
Nédia de Castilhos Ghisi ◽  
Maria Antônia Michels-Souza
Keyword(s):  
River Basin ◽  
Fish Species ◽  
Sexual Maturity ◽  
Gonadosomatic Index ◽  
Reproductive Period ◽  
Maturity Stage ◽  
Reproductive Process ◽  
Maturation Stages ◽  
High Degree ◽  
Iguaçu River

The reproductive process promotes morphophysiological and behavioral changes in fish species throughout their life cycle. Its success is vital to define their resilience in the environment. This study aimed to evaluate the reproductive biology of the endemic fish species Astyanax bifasciatus in a tributary of the Lower Iguaçu River Basin, Paraná, Brazil. Fish were collected monthly at four sites along the Jirau Alto River in the city of Dois Vizinhos from October 2015 to September 2016. A standardized catch effort with gill nets and fish traps was used. In the laboratory, standard length and total weight were recorded. After anesthesia, the animals were sectioned to macroscopically determine the sex, sexual maturity stage, and presence of celomatic fat. The gonads and liver were removed to determine the gonadosomatic and hepatosomatic indexes, respectively. A total of 160 individuals (104 females and 56 males) were used. The gonadosomatic index, frequency of the gonadal maturation stages, and condition factor showed a long reproductive period with two investment cycles for both sex. Length at first sexual maturity was 4.57 cm for females and 3.56 cm for males. The reproductive data corroborate the generalist profile of the species and demonstrate a high degree of adaptive capacity, even in smaller tributaries.

Aspects of the reproductive cycle and gonadal development of Murray cod, Maccullochella peelii peelii (Mitchell) (Percicthidae), in Lake Charlegrark and adjacent farm ponds, Victoria, Australia

1995 ◽  
Vol 46 (4) ◽  
pp. 723 ◽  
Author(s):  
GJ Gooley ◽  
TA Anderson ◽  
P Appleford
Keyword(s):  
Gonadosomatic Index ◽  
Testicular Tissue ◽  
Gonadal Development ◽  
Testicular Development ◽  
Male Fish ◽  
Farm Ponds ◽  
Macroscopic Classification ◽  
First Maturity ◽  
Murray Cod ◽  
Size At First Maturity

The gonadal development of Murray cod, Maccullochella peelii peelii, in Lake Charlegrark, Victoria, and adjacent farm ponds was evaluated. Gonadosomatic index, macroscopic classification and histological analysis were used to determine the age at first maturity and the gonadal development in this introduced population. There is a marked difference between the sexes in the size at first maturity, with females maturing at approximately 6 years of age and 2000 g in weight and males maturing at 3-4 years and 700 g. Gonadosomatic index data indicate that spawning occurs around November. Ovarian development in this species follows a pattern similar to that in a number of other teleosts. Testes have a lobular structure. Macroscopic evaluation of ovaries provided a good indication of the stage of the development of the gonad. However, the presence of spermatozoa throughout the year in the gonads of mature male fish makes the macroscopic evaluation of testicular development less reliable. Three cod, approximately 1% of the population, contained gonads with both ovarian and testicular tissue.

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