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

2011 ◽  
Vol 9 (3) ◽  
pp. 593-599 ◽  
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.

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

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.

scholarly journals Population biology of shrimp Macrobrachium jelskii (Miers, 1778) (Decapoda, Palaemonoidea) at the Grande River at northwest of the state of Minas Gerais, Brazil

2012 ◽  
Vol 24 (3) ◽  
pp. 266-275 ◽  
Author(s):  
Samara de Paiva Barros-Alves ◽  
Ariádine Cristine Almeida ◽  
Vivian Fransozo ◽  
Douglas Fernandes Rodrigues Alves ◽  
José Carlos da Silva ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Frequency Distribution ◽  
Population Biology ◽  
Abiotic Factors ◽  
Mesh Size ◽  
Minas Gerais ◽  
Reproductive Period ◽  
Length Frequency Distribution ◽  
Length Frequency ◽  
Monthly Basis

AIM: The population biology of the freshwater shrimp Macrobrachium jelskii was investigated here emphasizing the length-frequency distribution, sex ratio, reproductive period and juvenile recruitment. In addition, the abundance of individuals was correlated with the abiotic factors. METHODS: Samples were collected on a monthly basis from July 2005 to June 2007 along the river margin in shallow water of Grande River, at Planura region, State of Minas Gerais, Brazil (20º 09' S and 48º 40' W), using a trawl net (1.0 mm mesh size, and 2.0 m × 0.5 m wide). The fishing gear was handled by two people along the marginal vegetation of the Grande River in a course of 100 m, covered for one hour. In the laboratory, the specimens were identified, measured and sexed. RESULTS: A total of 2,789 specimens was analyzed, which corresponded to 1,126 males (549 juveniles and 577 adults) and 1,663 females (1,093 juveniles, 423 adults non-ovigerous and 147 ovigerous). The sex ratio differed significantly in favor of the females of M. jelskii (1:1.48; χ² = 103.95; p < 0.0001). The mean size of carapace length (CL) of females (6.32 ± 1.84 mm CL) was statistically higher than of males (5.50 ± 1.07 mm CL) (p < 0.001). The length-frequency distribution of the specimens revealed an unimodal pattern and non-normal distribution for males and females (W = 0.945; p < 0.01). No significant relationship between the abundance of M. jelskii and the environmental variables was observed (p = 0.799). CONCLUSION: The presence of ovigerous females and juveniles in the population suggests a continuous reproduction pattern and recruitment for M. jelskii at Planura region.

scholarly journals Seasonal changes in size, sex-ratio and body condition of the damselfishChromis chromisin the central Mediterranean Sea

2014 ◽  
Vol 94 (5) ◽  
pp. 1053-1061 ◽  
Author(s):  
Claudia Bracciali ◽  
Susanna Piovano ◽  
Gianluca Sarà ◽  
Cristina Giacoma
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Body Condition ◽  
Seasonal Changes ◽  
Marine Protected Area ◽  
Reproductive Period ◽  
Rocky Shores ◽  
Central Mediterranean ◽  
Monthly Basis ◽  
Spawning Period

Chromis chromisis one of the most abundant fish species on the Mediterranean rocky shores. Acting as a by-pass of nutrients from the pelagic to the rocky littoral system, it plays an important role as a resource provider and has a relevant function in the community assemblage.Chromis chromishas many of the characteristics required of an indicator species (e.g. it is easy to recognize in the field, small sized, widespread and abundant). In this study we focused on individual size, sex-ratio and body condition in a damselfish population occurring in a central Mediterranean marine protected area. Fishing trials on a monthly basis (April–November) allowed us to assess seasonal changes in population structure. Fish were measured and weighed and a subsample was aged and sexed. On average, males were larger than females. The allometric coefficient,b, for the whole population was 2.99; the maximum age recorded was 7.5 yr. Before reproduction sex-ratio was close to parity (M:F 1:0.78), while a larger proportion of females was captured during the reproductive period. In conclusion, our results show that the population dynamics ofC. chromisis influenced by both sex and size. Since males and females have different behavioural strategies, and since the length of the spawning period is shorter in the smaller than in the larger-sized individuals, this is reflected in temporal changes observed in the population structure.

scholarly journals The Biological Aspect of Mackerel Scad (Decapterus Macarellus Cuvier, 1833) In Samudera Hindia (West Sumatera Block)

Omni-Akuatika ◽  
2020 ◽  
Vol 16 (3) ◽  
pp. 92
Author(s):  
Heri Widiyastuti ◽  
Andina Ramadhani Putri Pane ◽  
Moh Fauzi ◽  
Thomas Hidayat
Keyword(s):  
Indian Ocean ◽  
Sex Ratio ◽  
Average Length ◽  
Mesh Size ◽  
Growth Patterns ◽  
Purse Seine ◽  
West Sumatra ◽  
The Indian Ocean ◽  
Biological Aspects ◽  
First Maturity

Mackerel scad (Decapterus macarellus) is one of the important economical caught in the Indian Ocean West Sumatra waters captured using purse seine. Increased production of mackerel scad will lead to increased exploitation, causing population changes. Therefore, research was carried out to find out the biological aspects of the fish so that resource management can be done. The sampling was conducted in Lampulo, Sibolga, and Air Bangis from February to November 2016 with total samples of 716 fishes. This research was conduct to study some biological aspects which consist of size distribution, length-weight relationship, sex ratio, gonad maturity level, the length at first capture, and length of the first maturity in Indian ocean west Sumatera waters. The results showed that the size of the mackerel scad had ranged between 16 - 33.6 cm FL and the average was 24.5 cm. Growth patterns are allometric negative, sex ratio male and female in an unbalanced condition. The mackerel scad is most caught by purse seine in maturity condition. The average length at first captured was 25.08 cm FL and length at first mature was 20.47 cm FL. These were an ideal biological condition and must be maintained because it provides an opportunity for fish to increase the population. The mesh size purse must follow the Ministry of Maritime Affairs and Fisheries Regulation Number 71/2016 that adjusted for minimum at 1 inch. Keywords: Mackerel scad, Indian Ocean, purse seine

scholarly journals Influence of the flood pulse on the reproduction of Tocantinsia piresi (Miranda Ribeiro) and Auchenipterus nuchalis (Spix & Agassiz) (Auchenipteridae) of the middle Xingu River, Brazil

2015 ◽  
Vol 75 (3 suppl 1) ◽  
pp. 158-167 ◽  
Author(s):  
TMS. Freitas ◽  
BS. Prudente ◽  
VA. Oliveira ◽  
MNC. Oliveira ◽  
EG. Prata ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Flood Pulse ◽  
Allometric Growth ◽  
Xingu River ◽  
Ratio Size ◽  
Flood Period ◽  
First Maturity ◽  
Size At First Maturity

Abstract This study investigates the influence of the flood pulse on the reproductive biology of the auchenipterids Tocantisia piresi (Miranda Ribeiro, 1920) and Auchenipterus nuchalis (Spix & Agassiz, 1829) from the middle Xingu River in the Brazilian state of Pará. The specimens were collected every three months between April, 2012, and January, 2014, covering four distinct periods (flood, ebb, dry, and filling). The sex ratio, size at first maturity, gonadosomatic index, and condition factor were analysed in the two species, and evaluated in the context of the different hydrological periods. A total of 897 specimens of T. piresi were collected, of which 467 were female, and 430 males, and 383 A. nuchalis (286 females and 97 males). In T. piresi, the sex ratio was biased only in the filling and ebb periods, whereas in A. nuchalis, it departed significantly from the expected ratio of 1:1 in all periods, with a predominance of females. The female T. piresi mature at a smaller size than the males, with the opposite of the pattern being recorded in A. nuchalis. In T. piresi, the breeding peak was observed during the low water periods, whereas in A. nuchalis, the peak was recorded in the flood periods. Male and female T. piresi presented similar positively allometric growth rates, whereas in A. nuchalis, growth was negatively allometric, but rates were different between genders. A higher condition factor was recorded in the females of both species during the ebb period. Overall, the results of this study reveals distinct flood pulse effects on the reproductive parameters of the two auchenipterid species studied; for A. nuchalis the spawning seems to happen at the flood period and for T. piresi at the dry season of the middle Xingu River.

scholarly journals Population structure, condition factor and reproductive period of Astyanax paranae (Eigenmann, 1914) (Osteichthyes: Characidae) in a small and old Brazilian Reservoir

2008 ◽  
Vol 51 (3) ◽  
pp. 503-512 ◽  
Author(s):  
Milza Celi Fedatto Abelha ◽  
Erivelto Goulart
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Total Population ◽  
Condition Factor ◽  
Regression Coefficient ◽  
Population Sample ◽  
Reproductive Period ◽  
Small Reservoir ◽  
Structure Condition ◽  
Maximum Value

The population structure, condition and reproductive period of Astyanax paranae adult individuals inhabiting a small reservoir were investigated. The fishes were quarterly captured from the riverine and lacustrine zones of the Alagados Reservoir, Paraná, Brazil, during 1996/1997 and 1998/1999. The sex ratio differed from 1:1 with the predominance of the females in all standard length classes and total population sample. The females showed higher condition than the males. Both the sexes presented lower mean condition values in April and higher mean condition values in July. The estimated values of the regression coefficient indicated isometric growth for the females and males. The gonadosomatic relationship reached a maximum value of 14.80% for the females and 8.43% for the males. The reproductive period possibly occurred from October to April.

scholarly journals Reproductive traits of horned octopus Eledone cirrhosa in Atlantic Iberian waters

2013 ◽  
Vol 93 (6) ◽  
pp. 1641-1652 ◽  
Author(s):  
Marcos Regueira ◽  
Angel F. González ◽  
Ángel Guerra ◽  
Amadeu Soares
Keyword(s):  
Sex Ratio ◽  
Reproductive Traits ◽  
Potential Fecundity ◽  
Spawning Period ◽  
North West ◽  
The North ◽  
Endogenous Reserves ◽  
First Maturity ◽  
First Time ◽  
Size At First Maturity

Length–weight relationships, sex-ratio, maturity patterns, size at first maturity, reproductive outputs, fecundity and spawning period of horned octopus Eledone cirrhosa in north-west Iberian coast are presented for the first time. Samples were collected between February 2009 and July 2011 in four fishing ports along the north-west Iberian coast: Burela in north Galician waters (NGW), Ribeira or Bueu in western Galician waters (WGW), and Aveiro in western Portuguese waters (WPW). A total of 4127 individuals (1042 males, 3079 females and six undetermined) were sampled. Individuals ranged from 45 to 191 mm dorsal mantle length (ML) and 15–1159 g body weight (BW). The overall sex-ratio was biased towards females, accounting for 74.71% of whole sample. Main spawning season of this species in north-western Iberian waters extends from May to June. Size at first maturity (ML50%) of males was 108.9 mm in NGW, 99.25 mm in WGW, and 91.4 mm in WPW, whereas ML50% for females were 134.5 mm, 121.4 mm and 100.8 mm, respectively. Potential fecundity was 2452.88 ± 36.4 oocytes per ovary (N = 697). Mean oocyte length was 3.89 ± 0.025 mm (N = 697). The average number of fully developed spermatophores in mature males was 86.55 ± 1.9 (N = 223) with a mean length of 44.97 ± 0.29 mm (N = 224). Potential fecundity in females was significantly (P < 0.05) correlated with ML and BW. Results obtained suggest that energy for gonad growth comes from the diet rather than endogenous reserves.

scholarly journals Sex Ratio And Size At First Maturity Of Blue Swimming Crab (Portunus pelagicus) Salemo Island Pangkep Regency

2016 ◽  
Vol 21 (1) ◽  
pp. 17 ◽  
Author(s):  
Muh. Saleh Nurdin ◽  
Syamsu Alam Ali ◽  
Dewi Yanuarita Satari
Keyword(s):  
Sex Ratio ◽  
Coral Reefs ◽  
Swimming Crab ◽  
High Demand ◽  
Chi Square ◽  
Portunus Pelagicus ◽  
Ratio Size ◽  
Chi Square Test ◽  
First Maturity ◽  
Size At First Maturity

Blue swimming crab (Portunuspelagicus) is aeconomical valuable fisheries importantcommodity  due to the high demand and availability jobs created for the fishermen. Due to their high demand blue swimming crab heavily exploited from Salemo Island. This study aimed at comparing the sex ratio and the size at first maturity of blue swimming crab caught in mangrove ecosystems, coral reefs, and seagrass. Sex ratio was analyzed using chi square test and the size at first maturity was analyzed using the Spearman-Karber formula. The results showed the sex ratio ofmales and femalessmall crab caught in every ecosystem is balanced. The size at first maturity of blue swimming crab caught in mangrove, seagrass and coral reefs, each to the male 81,08 mm, 102,36 mm and 102,87 mm in width and size of female 94,54 mm, 83,35 mm, 98,31 mm width. In a reference to government regulations, the blue male swimming crab caught in the coral reef and seagrass ecosystems have yet to size at first maturity is allowed to be captured. Keywords: blue swimming crab, sex ratio,size at first maturity, Salemo Island

scholarly journals Population structure of the crab Callinectes ornatus Ordway, 1863 (Brachyura: Portunidae) bycatch in shrimp fishery in northern Rio de Janeiro state, Brazil

2012 ◽  
Vol 12 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Caroline Cabral Tudesco ◽  
Laís Pinho Fernandes ◽  
Ana Paula Madeira Di Beneditto
Keyword(s):  
Population Structure ◽  
Rio De Janeiro ◽  
Carapace Width ◽  
Age Group ◽  
Shrimp Fishery ◽  
First Maturity ◽  
Janeiro State ◽  
Over Time ◽  
Swimming Crabs ◽  
Size At First Maturity

This study provides the first data on the population structure of swimming crab Callinectes ornatus Ordway, 1863 bycatch from coastal shrimp fishing in northern Rio de Janeiro State, Brazil (21º 30'-21º 50' S and 41º 05'-41º 07' W). Crabs were collected monthly from April 2006 to March 2007. A total of 5,611 specimens were analyzed, of which 3,951 were males and 1,660 ovigerous and non-ovigerous females. The overall sex ratio (2:1) differ significantly from the expected 1:1 proportion, being the mature males significantly predominant as bycatch in this fishery. The specimens' carapace width and weight varied from 27 to 126 mm (mean: 77.3 ± 12.3 mm) and 1.2 to 128.2 g (mean: 31.0 ± 14.4 g) for males, and 30 to 101 mm (mean: 63.4 ± 9.3 mm) and 1.7 to 66.0 g (mean: 16.4 ± 7.4 g) for ovigerous and non-ovigerous females. Seasonal comparisons did not reveal differences between the number of specimens captured in dry and rainy periods considering both sexes and maturity stages. The size at first maturity was 79 mm for males and 65 mm for females, and the carapace width-weight relationship indicated an alometric pattern for both sexes. The bycatch swimming crabs are locally used as bait, but the capture tendency for a specific sex/age-group can affect this population structure over time.

scholarly journals REPRODUCTIVE CHARACTERISTICS OF INDONESIA MAHSEER (Tor tambroides, Bleeker, 1854), IN TWO DIFFERENT RIVERS IN WESTERN SUMATERA

2014 ◽  
Vol 20 (2) ◽  
pp. 49
Author(s):  
Arif Wibowo ◽  
Siswanta Kaban
Keyword(s):  
Fisheries Management ◽  
Reproductive Period ◽  
High Variability ◽  
Seasonal Patterns ◽  
Reproductive Characteristics ◽  
Apparent Variation ◽  
First Maturity ◽  
Monthly Variations ◽  
Size At First Maturity ◽  
River Fish

The reproductive characteristics of mahseer, Tor. tambroides, were studied in Manna River and Batang Tarusan River, which are located on each side of Western Sumatera River. The reproductive period of T. tambroides is largely consistent with that described for the species in other areas, however monthly variations in the extent and timing of peak spawning are recorded. The analysis of the sex ratio indicates an increase in the percentage of females with size, more marked in largest sizes. Seasonal patterns in the occurrences of spawning showed that the spawning season in Manna River lasted was similar with that in Batang Tarusan River, although a second prominent increase of GSI was observed in April and September in Manna River, meanwhile the GSI of Batang Tarusan River fish were below 2 without an apparent variation. L50s of Manna River and Batang Tarusan River mahseer were estimated as 24.5 cm and 20.66 cm, respectively, indicating a high variability in size at first maturity of the mahseer population. Our study provides some important information on the reproductive biology of T. tambroides that will be helpful in similar studies and contributed to fisheries management of this species.

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