scholarly journals Reproductive strategy of spiny gurnard Lepidotrigla dieuzeidei Blanc and Hureau, 1973 from the south-eastern Adriatic Sea

2021 ◽  
Vol 62 (1) ◽  
pp. 49-62
Author(s):  
Tatjana Dobroslavić ◽  
Alexis Conides ◽  
Jadranka Sulić Šprem ◽  
Branko Glamuzina ◽  
Vlasta Bartulović
Keyword(s):  
Histological Analysis ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Stock Management ◽  
Valuable Contribution ◽  
Spawning Period ◽  
Mean Values ◽  
Multiple Spawning ◽  
Hydrated Oocyte ◽  
By Catch

This study provides the first data on the reproductive biology of the spiny gurnard Lepidotrigla dieuzeidei. A total of 1027 individuals were collected monthly from September 2011 to August 2012. The total length of the individuals in the sample ranged from 7.46 cm to 14.62 cm with a female to male ratio of 1 to 0.59. Positive allometric growth was observed for both females (b=3.07) and males (b=3.08). Variations of condition factor were similar in both sexes with mean values of 1.07 for females and 1.01 for males. The fish L. dieuzeidei had a long spawning period extending from November to July based on monthly values of gonadosomatic index. Histological analysis showed that this fish was multiple synchronous developments of ovaries with multiple spawning events. The ovaries were always represented with a group of primary oocytes and a diverse population of vitel-logenic oocytes, each specially recruited during the final stages of maturation in uniform or uneven phases. Batch fecundity was estimated gravimetrically using the hydrated oocyte method and was estimated to be around 558 to 10.230 oocytes per female. L. dieuzeidei is an important by-catch species and data from this study represent a valuable contribution to stock management.

scholarly journals Aspects of the biology of the Atlantic Midshipman, Porichthys porosissimus (Teleostei, Batrachoididae): an important by-catch species of shrimp trawling off southern Brazil

2000 ◽  
Vol 48 (2) ◽  
pp. 131-140 ◽  
Author(s):  
Marcelo Vianna ◽  
Acácio R. G. Tomas ◽  
José R. Verani
Keyword(s):  
Growth Parameters ◽  
Northern Coast ◽  
Pink Shrimp ◽  
Stock Management ◽  
Spawning Period ◽  
Management Measures ◽  
Shrimp Trawl ◽  
Trawl Fishing ◽  
By Catch ◽  
The Impact

Trawl fishing for pink shrimp (Farfantepenaeus brasiliensis and F. paulensis) catches large quantities of by-catch fish, discarded due to their having no commercial va)ue. As these species have rarely been studied, the impact of fisheries on these populations is not known. This contribution studies the biology of a species of no commercial value, the Atlantic midshipman Porichthys porosissimus. The last haul /Tom a commercial trawler, operating on the northern coast of São Paulo State and the southern coast of Rio de Janeiro State, was preserved (/Tom being discarded) and identified at the species leveI. It was observed that this fishery affects the juvenile population which is intluenced by the seasonal variation of the water masses. Growth parameters were estimated: L∞ = 37.0 cm, K = 0.285 year-1. Instantaneous mortality coefficients were estimated: 2=2.14, M=0.63, F= 1.51, S= 11.8 and E=0.71. Considering the intensive activity of the shrimp trawl tleet operating in this area, the deleterious action of trawling is considered as of high impact. The stock management measures applied for pink shrimp are without effect regarding P. porosissimus. which has its spawning period before the closed season and its recruitment peak after it. The results show overfishing and the need to apply measures to reduce trawling action, such as adequate policies, introduction of selectivity devices and the creation of exclusion zones for trawl fishing.

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.

Reproductive biology of the black-striped pipefish Syngnathus abaster Risso, 1827 (Pisces: Syngnathidae) in the Aegean Sea of Turkey

2018 ◽  
Vol 47 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Burcu Taylan ◽  
Gozde Ekin Tatarhan ◽  
Ozlem Aksoy ◽  
Mehmet Culha
Keyword(s):  
Reproductive Biology ◽  
Average Length ◽  
Gonadosomatic Index ◽  
Aegean Sea ◽  
Brood Pouch ◽  
Surface Water Temperature ◽  
Spawning Period ◽  
Total Length ◽  
Hydrated Oocyte ◽  
Length Relationship

Abstract The paper presents the results of research on the reproductive biology of Syngnathus abaster – a species distributed in Çandarli Bay. For this purpose, seine nets were collected from a depth of 0.5–2 m in 15 minute periods between April 2013 and March 2014, and a total of 185 individuals were sampled. It has been determined that 94 individuals (50.81%) were females, 79 were males (42.70%) and 12 were immature (6.49%). The sex ratio was 1:0.84. The average length values in female, male and immature individuals were 111.5 ± 7.35, 109.9 ± 11.08 and 79.8 ± 5.30 mm, respectively. The maximum mean surface water temperature is in spring and summer seasons. When Gonadosomatic Index (GSI%) values were examined, the spawning period of the species was indicated as spring and summer. Three groups of species were identified as maturing (diameter: 0.61–1.20 mm), mature (diameter: 1.21–1.70 mm) and hydrated oocytes (diameter: 1.71–2.10 mm) in ovaries of female individuals. The number of eggs in the brood pouch of pregnant male fishes was on average 48 (mean ± SD = 48 ± 14.09 eggs, range: 23–78 eggs). The hydrated oocyte/total length relationship was: y = 0.8651x – 84.332 (n = 14, r2 = 0.64) and the number of eggs/total length relationship in the brood pouch of pregnant males was: y = 1.0168x – 67.715 (n = 33, r2=0.58).

scholarly journals Comparative analysis of the reproductive activity of Leporinus piau (Characiformes: Anostomidae) in lentic and lotic environments

2020 ◽  
Vol 18 (4) ◽  
Author(s):  
Aline Virtude do Nascimento ◽  
Lucas Marcon ◽  
José Enemir dos Santos ◽  
Kleber Biana Santiago ◽  
Elizete Rizzo ◽  
...  
Keyword(s):  
Condition Factor ◽  
Gonadosomatic Index ◽  
Reproductive Activity ◽  
Mature Stage ◽  
Spawning Period ◽  
Sao Francisco River ◽  
São Francisco River ◽  
Lotic Environment ◽  
Lotic Environments ◽  
Três Marias Reservoir

Abstract In this study, we determined the main reproductive parameters of piau gordura, Leporinus piau, in two sections of the São Francisco River basin. Between May 2015 and April 2016, a total of 573 specimens were captured from a lentic environment (section 1), the Três Marias Reservoir (TMR), and a lotic environment (section 2), downstream of the TMR at the confluence of the São Francisco River (SFR) with the Abaeté River. Analysis of reproductive activity showed that L. piau from both sections reproduced, but females and males from section 1 exhibited higher total length, body weight, Fulton condition factor, and gonadosomatic index values, as compared to section 2. Sexual dimorphism was evident in the species, with females being larger than males. Moreover, males reached first gonadal maturation at a smaller size than females. The peak maturation/mature stage was observed in November/April for females and males in section 1 and in November/December in section 2, coinciding with high temperatures and precipitation in the region. In both sections of the river, L. piau exhibited the typical characteristics of partial spawning, with a prolonged spawning period, and preferential reproduction in lentic environments.

scholarly journals REPRODUCTIVE BIOLOGY OF THE MULLET LIZA FALCIPINNIS (VALENCIENNES, 1836) IN TWO AFRICAN COMPLEXS LAGOONS (EBRIÉ AND GRAND-LAHOU) (CÔTE D’IVOIRE)

2018 ◽  
Vol 6 (5) ◽  
pp. 114-127
Author(s):  
Ebram Luc Gervais ◽  
Soumaïla SYLLA ◽  
Tizié Thierry ZAN-BI ◽  
Boua Célestin ATSE
Keyword(s):  
Body Weight ◽  
Sex Ratio ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Fork Length ◽  
Total Body Weight ◽  
Hepatosomatic Index ◽  
Spawning Period ◽  
Total Body ◽  
Monthly Variations

The reproduction of Liza falcipinnis were investigated in both lagoons (Ebrié and Grand-Lahou) from January 2006 to december 2007. 2162 specimens were examined (914 and 1248 respectively in Ebrié and Grand-Lahou lagoons). Fork length was taken to the nearest 1 mm, and total body weight (TW) and eviscerated body weight (EW) to the nearest 0.1 g. The gonads and the liver were then established removed, weighted to the nearest 0.001g. The reproduced period of Liza falcipinnis was established by analysing the temporal evolution of the frequency of the maturity stages and the monthly variations in the gonadosomatic index (GSI), the hepatosomatic index (HIS) and the condition factor (K). Sex ratio was established taking into account the sex determinations. The size at which 50 % of the specimens became mature (FL50) was estimated. The sex ratio (1:1.24) and (1:1.40) observed respectively in Ebrié and Grand-Lahou lagoons were in favour of females. The first sexual maturity size was 21.0 cm (FL) for males and 27.9 cm (FL) for females in Ebrié lagoon and 24.7 cm (FL) for males and 27.9 cm (FL) for females in Grand-Lahou lagoon. Liza falcipinnis spawns in lagoon and the spawning period ranged from December to April.

Sexual development and demography of the rock hind Epinephelus adscensionis, a protogynous grouper, in the south-west Atlantic

2018 ◽  
Vol 69 (2) ◽  
pp. 300
Author(s):  
Simone Marques ◽  
Beatrice P. Ferreira
Keyword(s):  
Sexual Development ◽  
East Coast ◽  
Growth Parameters ◽  
Gonadosomatic Index ◽  
Export Markets ◽  
Spawning Period ◽  
Growth Coefficient ◽  
Multiple Spawning ◽  
North East ◽  
The North

This study reports on the pattern of sexual development and demography of Epinephelus adscensionis sampled on the north-east coast of Brazil. The species is a protogynous hermaphrodite, with males (26–44-cm total length, TL) transitioning from mature females (20–33cm TL). This species presented multiple spawning, with peaks in the gonadosomatic index indicating that the spawning period of the rock hind occurred along 3 months per year, where for 2008 was between August and October, and for 2009 was between July and September. Age was determined from otoliths and periodicity was validated from captive fish treated with tetracycline. The resulting von Bertalanffy growth parameters were as follows: theoretical maximum length (L∞) 34.82cm TL, growth coefficient (k) 0.26 and theoretical age at L=0 (t0) 0.86years. The size and age at sexual maturity for females were 20cm TL and 4 years. The total rate of mortality was 0.28year–1. Older fish were males and had a maximum longevity of 15 years. This species is an important resource for local communities, but is also currently caught by trap fisheries, which have been expanding in recent decades in response to demands of export markets. Lack of monitoring and management of these and other reef fisheries in north-east Brazil makes fishing sustainability uncertain.

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 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.

First report on the diet and reproductive biology of red-toothed triggerfish Odonus niger (Ruppell, 1836) from the south-eastern Arabian Sea

2021 ◽  
pp. 1-11
Author(s):  
Nitin Kanji Suyani ◽  
Mridula Rajesh ◽  
Kothanahally Mallegowda Rajesh
Keyword(s):  
Reproductive Biology ◽  
Arabian Sea ◽  
Feeding Habits ◽  
Gonadosomatic Index ◽  
Biological Information ◽  
The South ◽  
Spawning Period ◽  
South Eastern ◽  
Eastern Arabian Sea ◽  
Males And Females

Abstract The feeding habits and reproductive biology of red-toothed triggerfish Odonus niger (Ruppell, 1836) was analysed from 449 specimens collected from the Karnataka coast of the south-eastern Arabian Sea. Of the total stomachs examined, only 54 (12%) were empty and 395 contained food remains. The diet comprised crustacean remains (48.0%), zooplankton (21.4%), algae (16.5%), fish remains (6.1%) and cephalopod remains (5.3%) along with partially digested matter (2.3%) and detritus (0.4%). The species was found to be a generalist feeder and an omnivore. The overall sex ratio between males and females (1: 0.44) was significantly (P < 0.05) different. Histological examination of the ovaries indicated asynchronous ovarian development in females, with males maturing earlier than females. The gonadosomatic index (GSI) patterns of males and females, and the presence of ripe ovaries and spermatozoids suggested that April–May is the peak spawning period. The absolute and relative fecundity estimates ranged from 16,464–312,420 eggs and 251–2812 eggs g−1 respectively. Fecundity was positively correlated with total length and body weight. The biological information on diet composition and reproductive traits provided for the first time in this study can facilitate conservation, management and sustainable exploitation of this species in the study area.

Are there one or two stocks of Scoranza bleak - Alburnus scoranza Bonaparte, 1845 in Lake  Skadar (Montenegro)

2021 ◽  
Vol 40 ◽  
pp. 80-92
Author(s):  
Drago Marić ◽  
Katarina Burzanović
Keyword(s):  
Condition Factor ◽  
Accurate Determination ◽  
The Elderly ◽  
Total Sample ◽  
Population Variability ◽  
Winter Period ◽  
Small Fish ◽  
Mean Values ◽  
Weight Relationship ◽  
Lake Skadar

This paper provides the first comprehensive information on the Length-Weight Relationship (LWR) of Scoranza bleak (Alburnus scoranza) from the Lake Skadar. The results of the study showed that LWR was different in young and older individual fish. We concluded that no single regression would adequately describe the length-weight relationship for  Scoranza bleak in the winter period. Small fish, up to one year old, have positive allometric growth whereas older and larger, negative. The results of this study show that the animals grow equally in the same pattern in both localities (Raduš and Karuč) which shows that there are no two stocks as it was assumed in the past. The condition factor in young Scoranza bleaks was lower than in the elderly. Condition factor decreased significantly during the winter period in older specimens. Based on this, we conclude that Scoranza bleak during the winter is poorly fed/starved, which causes a decrease in the condition factor.Analysis of the total sample, of any species, cannot show by what rule the population grows, if infrapopulation variability is present, because the studied value will depend on the number of individual subgroups. If no infra-population variability is found, the required parameter for the entire population can be calculated. In order to determine population variability, multiple groups must be singled out. Preferably, the number of stratified samples should be at least 6 so that correlation-regression analysis can be performed. In stratified samples, the number of individuals should be between 30-40, for any parameter, in order to compare their mean values. The results of the study show that 50 individuals are sufficient for accurate determination of LWR (or ???? and b, ???? is a constant coefficient and b is the slope of the curve.), when it is determined that there is no intrapopulation variability.

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