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 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 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 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 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.

scholarly journals Seasonal variations in the population biology of Salmostoma bacaila (Cyprinidae) from a tributary of the Payra River, Bangladesh

2019 ◽  
pp. 113-119
Author(s):  
Ahamed Ahamed ◽  
Faruque Ahmed Zoarder ◽  
Jun Ohtomi
Keyword(s):  
Sex Ratio ◽  
Seasonal Variations ◽  
Population Biology ◽  
Sexual Maturity ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Spawning Season ◽  
Frequency Distributions ◽  
Size At Sexual Maturity ◽  
Management And Conservation

Some biological parameters of Salmostoma bacaila – including sex ratio, length-frequency distributions (LFDs), size at sexual maturity, spawning season, length-weight relationships (LWRs) and condition factor – were studied. Samples were collected seasonally during June 2017 to May 2018 from a tributary of the Payra River. The overall sex ratio was significantly different from the expected value of 1:1 (p < 0.001), in favour of male specimens. Females were significantly larger than males. Size at sexual maturity was estimated at 7.6~7.7 cm total length. Seasonal variations in the gonadosomatic index (GSI) indicate that the main spawning season is from spring to summer. The LWRs showed negative allometric growth in both sexes, but with clear seasonal variation. Fulton’s condition factor varied in both sexes and was attributed to variations in GSI with maturity. The fin¬dings of this study will be helpful for management and conservation of S. bacaila populations.

scholarly journals Reproductive patterns of bogue, Boops boops (Sparidae), in the southeastern Adriatic Sea

2017 ◽  
Vol 58 (1) ◽  
pp. 117-125
Author(s):  
Tatjana Dobroslavić ◽  
Renata Mozara ◽  
Branko Glamuzina ◽  
Vlasta Bartulović
Keyword(s):  
Total Population ◽  
Adriatic Sea ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Gonad Development ◽  
Size Class ◽  
Oocyte Diameter ◽  
Allometric Growth ◽  
Monthly Distribution ◽  
Boops Boops

The reproductive characteristics of bogue (Boops boops) in the southeastern Adriatic Sea are presented in this study. The analysis is based on 676 specimens caught by seine net from December 2011 to November 2012. Total length of females ranged from 13.3 to 29.3 cm and males from 15.1 to 26.3 cm. The overall sex ratio of females to males was 1:0.85 (χ2=4.314; P &lt; 0.05) with a slightly higher number of females in the largest size class. Length-weight relationship for the total population indicated negative allometric growth (b=2.911). Values of the condition factor are relatively low for both sexes. Maximum values were recorded in September 1.025 for females and 1.029 for males. Gonadosomatic index and histological examination showed that the spawning season of the bogue in the Adriatic is from January to May with peak in February. Six stages of gonad development were identified: immature, undergoing maturation, ripening, ripe, spawning and spent. The monthly distribution of the different sexual maturity stages and the frequency distribution of oocyte diameter revealed that this species is a batch spawner.

scholarly journals Pêche Et Caractéristiques Morphologiques D’un Poisson-Chat Endémique Synodontis Punctifer (Daget, 1964) Dans Le Barrage Électrique De Taabo (Côte d’Ivoire)

2018 ◽  
Vol 14 (15) ◽  
pp. 101
Author(s):  
Hervé Oussou Koffi ◽  
Diaha N’guessan Constance ◽  
Soro Yaya ◽  
N’Da Konan
Keyword(s):  
Sex Ratio ◽  
Condition Factor ◽  
Morphological Characteristics ◽  
Fishing Effort ◽  
Annual Production ◽  
Allometric Growth ◽  
Catch Per Unit Effort ◽  
Large Size ◽  
Unit Effort ◽  
Significant Difference

A study of Synodontis punctifer (family: Mochokidae) of Taabo Lake was conducted from October 2015 to September 2016. This was carried out so as to evaluate its quantity (biomass) caught by fishing and also its morphological characteristics. The fish were caught using gillnets at 4 sites of the lake and different measurements were made. The fishing effort was 23 to 11 fishermen / day in Taabo city, 17 to 11 fishermen / day in Courandjourou, 13 to 5 fishermen / day in Ahondo, and 8 to 3 fishermen / day in Taabo village. The catch per unit effort (CPUE) ranged from 17.7 to 3.7 g / fisherman / day, 9.2 to 1.2 g / fisherman / day, 8.3 to 0.7 g / fisherman /day, 8 to 1g / fisherman / day at Ahondo, Courandjourou, Taabo city and Taabo village, respectively. The overall annual production was estimated at 2199.3 kg, i.e. 817 kg (40%) at Ahondo, 788.3 kg (35%) at Courandjourou, 462.5 kg (20%) at Taabo, and 131.5 kg (5%) in Taabo village. The overall sex ratio (1: 1.33) was in favor of females. Individuals have negative allometric growth at all sites with values ranging from 1.72 to 2.89. The condition factor does not vary significantly between different categories of individuals (ANOVA, F = 2.79, p ˃ 0.05). A significant difference was observed between the average sizes of the individuals of the different sites (test, p˂0,05). The large size specimens were captured at Ahondo, mean (avg = 15.38 ± 1.68 cm FL). In Courandjourou, the sizes were intermediate (avg = 13.63 ± 1.64 cm LF). Smalls sizes have been observed in Taabo city (mean= 12.37 ± 1.24 cm FL) and Taabo village (mean= 15.58 ± 1.58 cm FL).

scholarly journals Age, Growth, Condition Factor and Reproduction of Planiliza abu (Mugiliformes: Mugilidae) in the Al-Diwaniya River, Middle of Iraq

2021 ◽  
pp. 20-29
Author(s):  
Abdul-Razak M. Mohamed ◽  
Mohanad O. Al-Jubouri
Keyword(s):  
Sex Ratio ◽  
Growth Performance ◽  
Performance Index ◽  
Condition Factor ◽  
Age Determination ◽  
The Body ◽  
Allometric Growth ◽  
Spawning Period ◽  
Relative Condition Factor ◽  
Gonad Somatic Index

The age, growth, relative condition factor, and reproduction of Planiliza abu (Heckel, 1843) from the Al-Diwaniya River, Iraq was described in samples obtained from October 2016 to September 2017, using different fishing gears. Total length and weight were measured, scales were used for age determination, and gonads were excised from the body cavity sexed and weighed. The lengths of the species ranged from 7.0 to 20.0 cm, and the most dominant length group was 13.0 cm. The length-weight relationship was W=0.0199*L2.821 revealing a negative allometric growth (b= 2.821). The mean relative condition factor (Kn) was calculated as 1.13 for females and 0.93 for males. Four ages were recognized for the species with mean total lengths of 10.2, 14.5, 39.0, 17.2 and 19.3 cm, respectively. The von Bertalanffy growth parameters based on back-calculated lengths were L∞= 23.4 cm, K=0.38 and to= -0.27. The growth performance index (Ø) of the species is computed as 2.32. The overall sex ratio (male: female) was 1:1.70. The gonad-somatic index (GSI) values of both sexes were highest in April, 8.5 for males and 11.6 for females and the lowest values in August, 0.22 for males and 0.75 for females, indicated that the spawning period was from April to May. Some biological properties such as lengths of individuals, negative allometric growth, ages from 1 to 4 years, values of ultimate growth (L∞) and growth performance index (Ø) and overall sex ratio were among those described for the species in other waters. These results can contribute to providing information for species management in the study river.

scholarly journals Some Biological Aspects of Al - Shabbot Arabibarbus grypus (Heckel, 1843) in Al-Diwanyia River, Middle of Iraq

2019 ◽  
Vol 27 (2) ◽  
pp. 306-316
Author(s):  
Mohanad O. Abdullah Al-Jubouri ◽  
Abdul-Razak M. Mohamed
Keyword(s):  
Sex Ratio ◽  
Condition Factor ◽  
Age Groups ◽  
Allometric Growth ◽  
Relative Condition Factor ◽  
Fish Catch ◽  
Total Fish ◽  
Biological Aspects ◽  
The Mean ◽  
Somatic Index

      Some biological characteristics of shabbot, Arabibarbus grypus (Heckel, 1843) in the Al-Diwaniya River, middle of Iraq were studied from October 2016 to September 2017. Water temperature ranged from 10.2oC in March to 32.8oC in August. A total of 853 fish were caught by seine, gill and cast nets and electro-fishing. A. grypus constituted about 6.27% of the total fish catch. The length-weight relationship was W=0.021*L2.7548 revealing an allometric growth. The mean relative condition factor was 0.91. Five age groups wore recorded and their mean total lengths were 20.2, 32.0, 39.0, 43.9 and 48.4 cm, respectively. The growth model of the species was  Lt= 58 [1-e -0.39 (t-0.313)]. The growth performance index (Φ) of A. grypus was computed as 3.11. The study declares that the species is a omnivore, feeding mainly on aquatic plants, insects, algae and detritus. The overall sex ratio (female: male) was 1.47:1. The highest values of gonado- somatic index (GSI) were 4.20 for female and 1.78 for males in April. The fecundity of the species ranged from 75600 to 124200 eggs. 

Reproductive cycle of the blue jack mackerel, Trachurus picturatus (Bowdich, 1825), off the Portuguese continental coast

2019 ◽  
Vol 32 ◽  
pp. 14
Author(s):  
Ana Maria Costa
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Condition Factor ◽  
Stock Assessment ◽  
Gonadosomatic Index ◽  
Biological Information ◽  
Hepatosomatic Index ◽  
Jack Mackerel ◽  
First Time ◽  
Monthly Variations

This work provides for the first time a description of the reproductive biology of Trachurus picturatus in Portuguese continental waters (between 41° 49′ and 36° 57′ latitude North). From January 2010 to December 2016 a total of 7409 individuals were sampled from bottom trawlers operating on the northwestern coast of Portugal. The observed sex ratio was 0.56 in favor of the females. Monthly variations in gonadosomatic index, proportion of actively spawning individuals, hepatosomatic index and Fulton′s condition factor were analyzed. More than 60% of spawning individuals were recorded in the first quarter, corresponding to the highest values of GSI, and Fulton's K and hepatosomatic index increased after the start of spawning. The morphometric relationships between total length and gutted weight showed significant correlations (high determination coefficient, r2 > 0.9) and isometric growth (b = 3) for both sexes. Results indicate that the spawning season of T. picturatus starts in December and extends until April–May, with a peak in March, which agrees with what has been indicated by other authors for the northeast Atlantic. This work provides important biological information on a species that although not subject to stock assessment is currently the 5th species landed by weight in Portuguese continental waters.

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