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 and reproductive parameters of the red-tailed catfish, Phractocephalus hemioliopterus (Pimelodidae: Siluriformes), from the Xingu River, Brazil

2019 ◽  
Vol 17 (2) ◽  
Author(s):  
Tiago Magalhães da Silva Freitas ◽  
Luciano Fogaça de Assis Montag
Keyword(s):  
Sex Ratio ◽  
Amazon Basin ◽  
Gonadosomatic Index ◽  
Management Strategies ◽  
Weight Ratio ◽  
High Water ◽  
Commercial Fish ◽  
Xingu River ◽  
Flood Period ◽  
First Maturity

ABSTRACT A field study of the sex ratio, length-weight ratio, body size at first gonadal maturation, and the breeding season of the red-tailed catfish, Phractocephalus hemioliopterus, was carried out in the region of the middle Xingu River in the eastern Amazon basin. The fish were sampled quarterly from September 2012 to January 2014 using gillnets and long lines. The sex ratio was balanced, and while males and females were similar in standard length, the females were heavier than the males, on average. The males presented negative allometric growth, and the females, isometric growth. The estimated size at first maturity was 77.8 cm. The variation in the gonadosomatic index and the greater frequencies of mature specimens indicated a reproductive peak at the beginning of the high-water (flood) period. As P. hemioliopterus is an important commercial fish, our findings will contribute to the future development of effective conservation and management strategies, such as minimum catch size and a close season that is appropriate for the region. These data will also provide important insights for the evaluation of potential impacts on the biology of this fish resulting from the construction of Belo Monte dam.

scholarly journals Feeding behaviour and reproductive biology of the shrimp scad Alepes djedaba(Forsskal, 1775) off Cochin coast, Kerala, south India

2019 ◽  
Vol 66 (3) ◽  
Author(s):  
N. Sajana ◽  
S. Bijoy Nandan ◽  
C. K. Radhakrishnan
Keyword(s):  
Sex Ratio ◽  
Feeding Behaviour ◽  
Feeding Habits ◽  
Gonadosomatic Index ◽  
Feeding Intensity ◽  
Ratio Size ◽  
Maturation Stages ◽  
Food And Feeding ◽  
First Maturity ◽  
Size At First Maturity

Food and feeding habits, sex ratio, spawning behaviour, size at first maturity, fecundity and ova diameter of the shrimp scad Alepes djedaba (Forsskal, 1775) exploited off Cochin coast, Kerala are presented in this study. A. djedabat is a pelagic carnivore, with a preference for fishes. Low gastrosomatic index (GaSI) values and very low feeding intensity during spawning season indicated poor feeding behaviour during the period. The sex ratio did not deviate from the expected 1:1 ratio. Size at first maturity was estimated to be193 mm for male and 174 mm for female. Monthly gonadosomatic index (GSI) values, monthly distribution of gonadal maturation stages and ova diameter revealed that the species had a prolonged breeding season from June to September with a peak in July. Estimated absolute fecundity was 59,744 to 3,30,190 with an average of 1,94,965 eggs.

scholarly journals Length-weight relation, condition factor and gonadosomatic index of the whitemouth croaker, Micropogonias furnieri (Desmarest, 1823) (Actinopterygii: Sciaenidae), caught in Lençóis Bay, state of Maranhão, eastern Amazon, Brazil

2017 ◽  
Vol 65 (1) ◽  
pp. 1-8 ◽  
Author(s):  
James Werllen de Jesus Azevedo ◽  
Antonio Carlos Leal de Castro ◽  
Marcelo Henrique Lopes Silva
Keyword(s):  
Sex Ratio ◽  
Rainy Season ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Length Distribution ◽  
The State ◽  
Allometric Growth ◽  
First Semester ◽  
Length Relationship ◽  
Micropogonias Furnieri

Abstract The whitemouth croaker, Micropogonias furnieri, which is exploited off the state of Maranhão, Brazil, reinforces the need for maintenance programs of natural stocks of this species to assist in the management of this exploited resource. The aim of the present study was to describe aspects regarding its reproductive characteristics (gonadosomatic index and condition factor) and also the length distribution and weight-length relationships. The fish were caught in Lençóis Bay in the state of Maranhão (eastern Amazon) between June 2010 and July 2011. A total of 570 individuals were caught (318 males and 252 females). Differences in length were found between the sexes, with females larger than males. The sex ratio indicated a tendency for females to be more abundant in the rainy season (first semester), whereas males predominated in the dry season (second semester). The weight-length relationship indicated negative allometric growth for both sexes. The analysis of the variation in the condition factor suggests that lower values coincided with higher gonadosomatic index values and that this factor is a good reproductive indicator for M. furnieri in the region.

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 The length-weight relationship, condition factor and reproductive biology of Pseudotolithus (p) senegalensis (valenciennes, 1833) (croakers), in Tombo western rural district of Sierra Leone

2014 ◽  
Vol 14 (66) ◽  
pp. 9376-9389
Author(s):  
JO Olapade ◽  
◽  
S Tarawallie
Keyword(s):  
Sex Ratio ◽  
Sierra Leone ◽  
Reproductive Biology ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Hepatosomatic Index ◽  
Allometric Growth ◽  
Spawning Period ◽  
Weight Relationship ◽  
Spawning Behaviour

The length – weight relationship (LWR), condition factor (K), sex ratio, gonadosomatic index (G S I) and hepatosomatic index (H S I) of 412 specimens of Pseudotolithu s s enegalensis (Valenciennes, 1833) from Tombo , a coastal fishing community in the western rural district of Sierra Leone were studied for twelve months . Samples used for the study were collected from the catches of artisanal fishers and measurement s of length and weight of samples were done in situ using the facilities of the Ministry of Fisheries and Marine Resources. Samples for the reproductive study were preserved in an ice box and taken to the laboratory of the Department of Aquaculture and Fisheries Management, Njala University , Sierra Leone for analysis. The parameters "a" and "b" of the length - weight relationship were estimated using the equation described by Ricker ( W = aL b ) while the condition factor was calculated using Fulton`s equation (K = W1 00 / L 3 ) . The reproductive biology of the fish was estimated using Gonadosomatic index ( GSI ) and Hepatosomatic index ( H S I ) . The combined LWR for both sexes showed that a, b and r values were – 2.57 , 3. 3 5 and 0. 899 , respectively. The r – values obtained show a strong linear relationship between the length and weight of the species. The length - weight relationship indicated allometric growth for P . senegalensis in the study area. The condition factor (K) varied from 0.64 – 1.0 ; this may be attributed to environmental conditions of the water . The species clearly exhibited a positive allometric growth pattern ( tα ( 2) , 0.05, 411 > 1.965) . The sex ratio of males to females was 1:1. 15 and was not significantly different from the expected 1:1 ratio. Estimation of GSI and HSI was carried out from December, 2010 to May, 2011 to determine the spawning behaviour of P. senegalensis . The mean GSI obtained indicate d that March and April , respectively are the two peak spawning period for the species . Gonado somatic index ranged between 1.1 % and 2.8% for the females. The results of this study revealed that P. senegalensis doe s not have obligatory spawning month but exhibit multiple spawning behaviour. T he length - w eight relationships and condition factor of the study indicated that the fish were thriving very well in the coastal water of Sierra Leone. Sustainable management of the species , therefore , require s that the environment be protected against anthropogenic pollution and imposition of closed fishing season especially during the t wo peak spawning period is recommended to enable the species recruit effectively.

scholarly journals Trophic ecology of the fish Leporinus piau (Characiformes: Anostomidae) in an area influenced by a dam in the Parnaíba River

2020 ◽  
Vol 68 (2) ◽  
Author(s):  
Francimário S. Feitosa ◽  
Carla Ferreira Rezende
Keyword(s):  
Reproductive Strategies ◽  
Life History Theory ◽  
Trophic Ecology ◽  
Niche Breadth ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Length Relationship ◽  
Hydroelectric Dam ◽  
First Maturity ◽  
Size At First Maturity

Introduction: Hydroelectric dams have several impacts on migratory fish, such as decreasing their abundance, local extinctions, and changes in the assemblage structure. Objective: To investigate the trophic and reproductive strategies of Leporinus piau upstream and downstream from a hydroelectric dam in the Parnaíba River. Methods: We identified food items and calculated trophic niche breadth in both sites to characterize the feeding strategy. We conducted permutational multivariate analysis of variance (PERMANOVA) to determine differences in diet between sites, followed by a SIMPER analysis in order to show which items were the most dissimilar. To characterize the reproductive strategy, we analyzed weight/length relationship, body condition factor, gonadosomatic index, and size at first maturity. Results: Leporinus piau was classified as an omnivore with a predominantly plant-based diet at both sites. The diet and niche breadth varied between sites. The condition factor differed between sites while size at first maturity differed between sites and sexes. Conclusions: Leporinus piau variations upstream and downstream from a hydroelectric dam in the Parnaíba River are results of differences in life histories traits, as identified in the life history theory, which clarifies the differences on trophic and reproductive strategies.

scholarly journals Reproductive tactics used by the Lambari Astyanax aff. fasciatus in three water supply reservoirs in the same geographic region of the upper Iguaçu River

2010 ◽  
Vol 8 (4) ◽  
pp. 885-892 ◽  
Author(s):  
Juliano Pilotto Abelardino da Silva ◽  
Adriane Esquivel Muelbert ◽  
Elton Celton de Oliveira ◽  
Luís Fernando Fávaro
Keyword(s):  
Sex Ratio ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Geographic Region ◽  
The Other ◽  
Allometric Growth ◽  
Reproductive Tactics ◽  
Average Value ◽  
Water Supply Reservoirs ◽  
Iguaçu River

The species Astyanax aff. fasciatus was investigated as regards differences in reproductive tactics in three reservoirs with different ages (Iraí, Piraquara and Passaúna) located in the same geographic region. The biological material was obtained through monthly collections carried out from july/2006 to june/2007. The average value of the gonadosomatic index (GSI) in Passaúna reservoir was significantly higher in relation to the values obtained in the other reservoirs. Spawning was total in Iraí reservoir and partial in the others. Allometric growth of the species was negative in Iraí reservoir and positive in the others. The highest condition factor value was estimated in Iraí reservoir, followed by Piraquara and Passaúna reservoirs, respectively. Females predominated in all of the reservoirs during the study period. The sex ratio per length class showed, for the three reservoirs, the predominance of males in the smaller length classes. These results verified that the species uses distinct reproductive tactics in the analyzed reservoirs and that these tactics seem to reflect the degree of stabilization of each environment.

scholarly journals PERTUMBUHAN, FAKTOR KONDISI, DAN BEBERAPA ASPEK REPRODUKSI IKAN LEMURU (Amblygaster sirm, Walbaum 1792) DI PERAIRAN SELAT SUNDA

2017 ◽  
Vol 9 (1) ◽  
pp. 43
Author(s):  
Nidya Kartini ◽  
Mennofatria Boer ◽  
Ridwan Affandi
Keyword(s):  
Sex Ratio ◽  
Condition Factor ◽  
Growth Parameters ◽  
Sampling Technique ◽  
Biological Information ◽  
Male And Female ◽  
Conservation Measure ◽  
Males And Females ◽  
First Maturity ◽  
Size At First Maturity

Ikan lemuru (Amblygaster sirm) merupakan salah satu komiditas utama di Selat Sunda yang menjadi target nelayan di Pelabuhan Perikanan Pantai Lebuan. Informasi biologi dibutuhkan untuk menyusun langkah konservasi ikan lemuru. Penelitian ini bertujuan untuk menganalisis kondisi biologis ikan lemuru di perairan Selat Sunda melalui pengkajian parameter pertumbuhan, faktor kondisi, dan beberapa aspek reproduksi. Pengambilan ikan contoh dilakukan pada bulan April-Agustus 2015 dari hasil tangkapan nelayan yang didaratkan di PPP Labuan, Banten menggunakan teknik Penarikan Contoh Acak Berlapis. Jumlah ikan contoh yang diambil selama penelitian sebanyak 527 ekor ikan jantan dan 245 ekor ikan betina. Hasil penelitian menunjukkan bahwa pola pertumbuhan ikan lemuru jantan dan betina adalah isometrik, nilai faktor kondisi ikan lemuru jantan berkisar 0,9346 – 1,0294 dan betina berkisar 0,9401 – 1,0738, parameter pertumbuhan L∞, K, dan t0 pada ikan jantan adalah 248,80 mm; 0,24/tahun;dan -0,38. Adapun parameter (L∞, K, dan t0) pada ikan betina adalah 235,26 mm; 0,46/tahun, dan -0,20. Nisbah kelamin ikan lemuru jantan dan betina TKG IV adalah 0,75:1. Ukuran pertama kali matang gonad (Lm) ikan lemuru jantan dan betina adalah 188 mm dan 186 mm. Sedangkan ukuran pertama kali tertangkap (Lc) ikan lemuru jantan dan betina adalah 172 mm dan 173 mm. Musim pemijahan ikan lemuru diduga terjadi pada bulan Mei dan Juli.The spotted sardinella (Amblygaster sirm) was one of main commodities in the Sunda Strait that maily targeted by fishers in Labuan Coastal Fishing Port, Banten. The biological  information  needed to setup conservation measure of the spotted sardinella. This research aims to analyse the biological conditions of spotted sardinella in the Sunda Strait by reviewing parameters of growth, condition factor, and some reproduction aspect. Research was conducted in April-August 2015 in Labuan Coastal Fishing Port, Banten by using Random Stratified Sampling technique. About 700 samples (527 male and 245 female fishes) collected during study. The results showed that the growth pattern of male and female were isometric, value of condition factor for male ranged from 0,9346 – 1,0294 and for female ranged from 0,9401 – 1,0738. The estimated growth parameters (L∞, K, and t0) for male were 248,80 mm; 0,24 year-1;and -0,38 respectively. While, the parameters (L∞, K, and t0) of female were 235,26 mm; 0,46 year-1;and -0,20 respectively. The sex ratio between males and females for spotted sardinella was 0,75:1. The size at first maturity (Lm) of male and female were 188 mm and 186 mm, respectively. In addition, the size a first caught (Lc) of male and female was 172 mm and 173 mm, respectively. Thespawning season spotted sardinella possibly occurs in May and July.

scholarly journals Size, sex and maturity of the squid Lolliguncula diomedeae (Cephalopoda: Loliginidae) in the Gulf of Tehuantepec, México.

2015 ◽  
Vol 7 (1) ◽  
pp. 79-87
Author(s):  
María del Carmen Alejo-Plata ◽  
José Luis Gómez-Márquez ◽  
Jorge Eduardo Herrera-Galindo
Keyword(s):  
Sexual Maturity ◽  
Gonadosomatic Index ◽  
Reproductive Activity ◽  
Allometric Growth ◽  
Relationship Type ◽  
Length Relationship ◽  
Gulf Of Tehuantepec ◽  
Males And Females ◽  
First Maturity ◽  
Size At First Maturity

There is practically no information on the biology of Lolliguncula (Loliolopsis) diomedeae. We analyzed specimens caught in four shrimp fishing trips in the Gulf of Tehuantepec in 1999-2001, 2004 and 2006.Sexual maturity and gonadosomatic index (GSI) were used as indicators of reproductive activity. A total of 1 200 individuals were captured, 89% female. Females ranged from 35 to 97mm in mantle length (LDM),with a mode at 80mm and weights 2 to 30,9g; males 20,7 to 65mm LDM with a mode at 35-40mm and weights from 0,4 to 12g. Differences in the LDM and the PT between males and females were significant (KS, p<0,05). The sex ratio was 8:1 H:M (p <0,05). The weight-length relationship type is potential for both sexes, with a negative allometric growth.83% of mature females had high IGS values, in contrast to less than 20% of mature males. The size at first maturity (L50) indicates that males (42,7mm LDM) mature when shorter than females (74,5mm LDM). Maturity, IGS and oceanographic features of the Gulf of Tehuantepec indicate that L. diomedeae spawn there.

scholarly journals Population structure and reproductive biology of Loricariichthys melanocheilus Reis & Pereira, 2000 (Siluriformes: Loricariidae) in the rio Ibicuí, Brazil

2015 ◽  
Vol 13 (2) ◽  
pp. 371-382 ◽  
Author(s):  
Éverton Luís Zardo ◽  
Everton Rodolfo Behr
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Reproductive Biology ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Maturity Stage ◽  
Allometric Growth ◽  
Males And Females ◽  
Lotic Environments ◽  
Gonadal Condition

The objective of this study was to analyze population structure (spatial distribution, seasonal distribution and distribution by length classes, sex ratio and length-weight relationship) and aspects of the reproductive biology of Loricariichthys melanocheilus. Fish were sampled bimonthly using gillnets and trammel nets in lentic and lotic environments in the rio Ibicuí, between the years 2000 and 2001. Were collected 410 specimens: 230 females, 164 males and 16 specimens whose sex could not be determined. A greater number of specimens were collected in October/November and December/January and in lentic environments. The greater length classes had a higher amount of females (p < 0.05) and the sex ratio in all sampling periods was 1.38 females per male. Both males and females showed positive allometric growth (b = 3.299 and b =3.487, respectively). The highest values for gonadosomatic index (GSI) and gonadal condition factor (K) were observed from August/September and peaked in October/November, just like the highest frequencies of females at maturity stage C (mature), which is indicative that the breeding season occurs at this time.

Sign in / Sign up

Export Citation Format

Share Document