scholarly journals Identifying peak breeding season and estimating size at first maturity of mud crab (Scylla olivacea) from a coastal region of Bangladesh

Heliyon ◽  
2020 ◽  
Vol 6 (6) ◽  
pp. e04318
Author(s):  
Muhammad Yousuf Ali ◽  
Md. Billal Hossain ◽  
Sattyajit Sana ◽  
Muhammad Abdur Rouf ◽  
Sajeda Yasmin ◽  
...  
Keyword(s):  
Breeding Season ◽  
Coastal Region ◽  
Mud Crab ◽  
First Maturity ◽  
Size At First Maturity

Reproductive characteristics of the freshwater shrimp, Macrobrachium macrobrachion (Herklots, 1851) in the water bodies of Benin, West Africa

Crustaceana ◽  
2019 ◽  
Vol 92 (3) ◽  
pp. 269-294
Author(s):  
G. Koussovi ◽  
F. Niass ◽  
C. A. Bonou ◽  
E. Montchowui
Keyword(s):  
West Africa ◽  
Reproductive Biology ◽  
Breeding Season ◽  
Developmental Stages ◽  
Freshwater Shrimp ◽  
Breeding Parameters ◽  
The One ◽  
First Maturity ◽  
Somatic Index ◽  
Size At First Maturity

Abstract The palaemonid shrimp Macrobrachium macrobrachion is widely distributed in coastal rivers, estuaries and inland waters of West Africa. This species is economically important because it is the one of the two main freshwater shrimp commercially exploited by artisanal fisheries in southern Benin, besides showing great potential for aquaculture. Despite this, little is known about its reproductive biology in the natural environment. Considering these facts, the present study aimed to establish some breeding parameters for M. macrobrachion in Benin. Overall, 2424 specimens were collected between May 2015 and October 2016. Monthly changes in gonado-somatic index (GSI) and hepato-somatic index (HSI) suggest that the breeding season runs from July to October. In the Ouémé River Delta, the estimated size at first maturity is 8.16 cm TL in females, while it is 7.47 cm TL in males. In the Mono River/Grand-Popo Lagoon complex, the size at first maturity is 7.27 cm TL in females while it is 6.56 cm TL in males. The structure of the ovary as observed in females from either site just before spawning, shows the presence of two types of oocytes at different sizes and various developmental stages. Analysis of such ovarian structure suggests that M. macrobrachion has a synchronous oogenesis with a breeding season limited to a few months of the year. Fecundity was found to be between 3144 and 26 489 eggs in the Ouémé Delta, while it goes from 3124 to 22 660 eggs in the Mono River/Grand-Popo Lagoon complex. The present study provides important information on the reproductive biology of M. macrobrachion and of freshwater shrimp in general, and can also serve as a significant foundation for the aquaculture of species of freshwater shrimp.

Mud crab, Scylla olivacea: fattening practices in Bangladesh.

2020 ◽  
Author(s):  
Md. Younus Mia
Keyword(s):  
Operating Cost ◽  
Coastal Region ◽  
Market Value ◽  
High Survival ◽  
Net Income ◽  
Market Demand ◽  
High Survival Rate ◽  
Mud Crab ◽  
Mangrove Crab ◽  
Good Market

Abstract Fattening mud or mangrove crab, Scylla olivacea, has been practised in recent years in brackishwater ponds in Bangladesh. It is a relatively new practice in the country. Small- to medium-sized and even large but gonadal immature crabs that have low market value are bought from farmers, fishers, or from the market and stocked in fattening ponds. Fattening of crab is profitable because of fast turnover, low operating cost, high survival rate and good market demand. Two types of brackishwater earthen ponds are used to fatten crabs. One type is connected to the river through inlets and outlets to exchange water during high and ebb tides. Another type is not connected to the river but water is pumped into and discharged from the pond. The importance of fattening has been recognized as a source of income and employment to alleviate the poverty of coastal people. Through this technology, pond and ditches in the coastal region can be used throughout the year. On the basis of an interview with farmers, a net income of Tk 3,800 (US$ 65.50) can be achieved from a 120 m2 pond using the crab fattening technology. There is potential to expand crab fattening practices in coastal areas. However, an inadequate supply of stockable crab and feed are major constraints in this sector.

scholarly journals Fecundity, histomorphology of the ovary and size at first maturity of Neolissochilus hexagonolepis (McClelland) in Tamor River, Nepal

2020 ◽  
Vol 12 (3) ◽  
pp. 401-410
Author(s):  
Suren Subba ◽  
Vinod Kumar Mahaseth ◽  
Bharat Raj Subba ◽  
Shyam Narayan Labh
Keyword(s):  
Fishery Management ◽  
Fork Length ◽  
Reproductive Traits ◽  
Breeding Period ◽  
Absolute Fecundity ◽  
Fish Samples ◽  
Measuring Tape ◽  
The Mean ◽  
First Maturity ◽  
Size At First Maturity

Neolissochilus hexagonolepis (McClelland, 1839) is one among the notable species in snow-fed torrential rivers of Nepal. The present study attempts to investigate some reproductive traits of N. hexagonolepis, including the length at first maturity, fecundity and its relationships with biometric variables like lengths (TL, SL, and FL) and weights (TW and OW) of the fish in the mid-reaches of Tamor River, Nepal. A total of 109 fish samples were collected from the river. For each individual, total length (TL), standard length (SL) and fork length (FL) were measured in a fully stretched condition to the nearest 1mm using a measuring tape and graduated ruler, while total weight (TW) and ovary weight (OW) was measured using a digital balance with the precision of 0.01 g. The mean absolute fecundity (F) was 8356.44 ± 4612.59 and ranged from 2398.6 to 20160. SL was more significantly correlated with absolute fecundity (R2=0.59; p<0.001) than other body metrics. The results showed that female individuals of N. hexagonolepis attained the first sexual maturity at TL 32.9 cm. N. hexagonolepis exhibited a protracted breeding period with its ovaries passing through six different stages of maturation. The finding of the present study may serve as a protocol for fishery biologists and managers to promulgate adequate regulations for continual fishery management in the River Tamor, Nepal.

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.

scholarly journals length at first maturity of two species of lantern sharks (etmopterus spinax and etmopterus pusillus) off southern portugal

2005 ◽  
Vol 85 (5) ◽  
pp. 1163-1165 ◽  
Author(s):  
rui coelho ◽  
karim erzini
Keyword(s):  
Deep Water ◽  
Shark Species ◽  
Fishing Mortality ◽  
Portuguese Coast ◽  
Southern Portugal ◽  
First Maturity ◽  
Late Maturation ◽  
Size At First Maturity

etmopterus spinax and etmopterus pusillus are captured in large quantities in some deep-water fisheries along the portuguese coast and are always discarded. specimens were collected from february 2003 to may 2004 from deep-water fisheries and classified as mature or immature. maturity ogives were fitted and size at first maturity estimated for each sex of each species. both species are late maturing, with the maturity sizes varying between 75% and 87% of the maximum observed sizes, depending on species and sex. for both species, females tended to mature at and grow to larger sizes than males. the late maturation of these deep-water shark species makes these populations extremely vulnerable to increasing fishing mortality.

scholarly journals Crab Fattening in Bangladesh: A Socio-economic Perspective

2015 ◽  
Vol 6 (1) ◽  
pp. 145-152 ◽  
Author(s):  
Z Ferdoushi
Keyword(s):  
Young People ◽  
Natural Resources ◽  
Economic Condition ◽  
Coastal Region ◽  
The Other ◽  
Small Scale ◽  
Mud Crab ◽  
Economic Perspective ◽  
Negative Perception ◽  
Southwest Part

Thestudy was conducted to assess the socio-economic condition of the crab fatteners in the southwest part of Bangladesh.About 52% farmers have an experience of 5 to 10 yearsof indicating that involvement in mud crab fattening is the recent development and innovation in those areas.The Hindus in the coastal region found to have more interest in crab farming. On the other hand, about 27% Muslim were also found to involve in this farming.Comparativelyhigher involvements of Hindus farmers were found in Khulna region. Mostly young people found to have more involvement ranging from 26 to 35 years old which constituted more than 38% of the total interviewed population. About 40% farmers showedhigher satisfaction bycrab fattening while,fewfarmers reported some negative perception. Most of their farmingwere small scale and the farmers also accounted the higher seed cost with low profitability. However, well developedco-operation and partnershipbetween farmers, fishermen, middlemen and wholesaler can also improve this sector for sustainable development.DOI: http://dx.doi.org/10.3329/jesnr.v6i1.22056 J. Environ. Sci. & Natural Resources, 6(1): 145-152 2013

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