Reproductive biology and population structure ofAxianassa australis(Crustacea, Axianassidae) on a sand-mud flat in north-eastern Brazil

2015 ◽  
Vol 95 (4) ◽  
pp. 735-745 ◽  
Author(s):  
M.L. Botter-Carvalho ◽  
L.B. Costa ◽  
L.L. Gomes ◽  
C.C.C. Clemente ◽  
P.V.V. Da C. Carvalho
Keyword(s):  
Population Structure ◽  
Reproductive Biology ◽  
Somatic Growth ◽  
Allometric Growth ◽  
Differential Growth ◽  
Left Handedness ◽  
Eastern Brazil ◽  
North Eastern ◽  
Mud Flat ◽  
Major Cheliped

The life history of the mud shrimpAxianassa australis, a common and widespread burrower inhabiting coastal mangroves and mud flats, is poorly known. This contribution presents the first information about the population structure, reproductive biology and fecundity ofA. australis, based on individuals collected from September 2011 to December 2012 on Casa Caiada Beach, located in a densely urbanized area in north-eastern Brazil, using a yabby pump. The sex ratio did not depart significantly from the expected 1:1 proportion. A significant trend of left-handedness of the major cheliped was observed in the population. Females reached a larger maximum cephalothorax length (CL) than males. The differential growth between CL and the propodus of the major cheliped showed negative allometric growth for females and positive allometric growth for males, suggesting a trade-off between somatic growth and reproductive effort. Females bearing uneyed orange embryos predominated during all months in which ovigerous females were collected. Mean fecundity was 2379 eggs, ranging from 5 (7.55 mm CL) to 8300 (14.19 mm CL) eggs per female. About 71% of the variation in the number of eggs carried per female was explained by CL. The mean egg size correlated negatively with fecundity, indicating that large females ofA. australisproduce more and larger eggs than smaller females.

Reproductive biology of two Cattleya (Orchidaceae) species endemic to north-eastern Brazil

2006 ◽  
Vol 21 (2) ◽  
pp. 85-91 ◽  
Author(s):  
ERIC CAMARGO SMIDT ◽  
VIVIANE SILVA-PEREIRA ◽  
EDUARDO LEITE BORBA
Keyword(s):  
Reproductive Biology ◽  
Eastern Brazil ◽  
North Eastern

scholarly journals Population status and fishery potential of the mangrove crab,Ucides cordatus(Linnaeus, 1763) in North-eastern Brazil

2016 ◽  
Vol 98 (2) ◽  
pp. 299-309 ◽  
Author(s):  
Luciana Cavalcanti Maia Santos ◽  
Marcelo Antonio Amaro Pinheiro ◽  
Farid Dahdouh-Guebas ◽  
Marisa Dantas Bitencourt
Keyword(s):  
Population Structure ◽  
Sustainable Use ◽  
Management Plan ◽  
Population Status ◽  
Ucides Cordatus ◽  
Crab Population ◽  
Eastern Brazil ◽  
North Eastern ◽  
Crab Density ◽  
Commercial Size

Ucides cordatusis a semi-terrestrial crab and key species endemic to mangrove areas of eastern Americas. In North-eastern Brazil this crab holds a major socio-economic function for artisanal fisheries, as in the São Francisco River Estuary (10°30′27″S 36°23′45″W). Nevertheless, decreases in this species’ stock have been reported since 2000, requiring assessments of the crab population for conservation and management purposes. This study aims at assessing the population status and the fishery potential of this species in the mangroves of this estuary and suggests strategies for its fishery and conservation, according to the guidelines of the National Management Plan forU. cordatusSustainable Use. Six different sites established in 30 km2of mangroves were sampled, with the density ofU. cordatusburrows estimated to evaluate the population structure using the measure of burrow diameters. Results show that the crab mean burrow size was 56.82 (±12.2) mm and that the medium-size crabs (40–70 mm) are the most abundant. The total mean crab density was 1.2 crabs m−2, from which the density of crabs in commercial size (0.85 ± 0.55 crabs m−2) was significantly higher than those in non-commercial size (0.35 ± 0.21 burrow m−2). These mangroves showed a high potential for the crab fishery, with an immediate extractive potential (IEP) of 71.2% and future extractive potential (FEP) of 28.8%. Nevertheless, a lower crab density, probably due to high crab mortality, mangrove deforestation for shrimp farming and high fishery pressure, is a limiting factor for local fishery. We conclude that mangrove areas more appropriate forU. cordatusfishery (extractive areas) show higher mean crab size, IEP and density of commercial crabs, wherein a fixed exploitation rate or/and a fixed escapement rule should be considered. Exclusion areas, intended for the conservation, show lower values of these population parameters and higher FEP, wherein the fishery should be prohibited. These management strategies should also be considered in other Brazilian mangrove areas showing similar crab population structure, thus contributing to the National Management Plan forU. cordatusSustainable Use.

scholarly journals First record of bilateral hypertrophy in chelas of Uca rapax male specimen (Crustacea, Decapoda, Ocypodidae) on the Brazilian coastline

2015 ◽  
Vol 8 ◽  
Author(s):  
Valéria Fonsêca Vale ◽  
Carlos Eduardo Rocha Duarte Alencar ◽  
Sávio Arcanjo Santos Nascimento Moraes ◽  
Fúlvio Aurélio Morais Freire
Keyword(s):  
Adult Male ◽  
Rio Grande ◽  
First Record ◽  
Normal Male ◽  
Male Specimen ◽  
Mangrove Area ◽  
Eastern Brazil ◽  
North Eastern ◽  
Major Cheliped

An adult male specimen ofUca rapax(Crustacea, Decapoda, Ocypodidae), containing bilaterally hypertrophied chelipeds, was found in the mangrove area of the Rio Grande do Norte state, north-eastern Brazil. The chelipeds are subequal in size and similar to the major cheliped of normal male specimens ofUca rapax. This paper is the first record of the aforementioned anomaly for the species from the Brazilian coastline.

Population dynamics of the white shrimp Litopenaeus schmitti (Burkenroad, 1936) on the southern coast of Pernambuco, north-eastern Brazil

2018 ◽  
Vol 99 (2) ◽  
pp. 429-435 ◽  
Author(s):  
Emanuell Felipe Silva ◽  
Nathalia Calazans ◽  
Leandro Nolé ◽  
Roberta Soares ◽  
Flávia Lucena Frédou ◽  
...  
Keyword(s):  
Maximum Yield ◽  
Total Mortality ◽  
White Shrimp ◽  
Fishing Mortality ◽  
Allometric Growth ◽  
Stock Status ◽  
Von Bertalanffy Model ◽  
Eastern Brazil ◽  
North Eastern ◽  
Yield Per Recruit

This study describes the structure, growth, mortality and stock status of Litopenaeus schmitti in north-eastern Brazil. A total of 1169 specimens were captured (491 males and 678 females) from August 2011 to July 2012. Specimens were weighed and the length of carapace (CL) and total length were measured. The biometric relationships were estimated through regression analysis and growth was described through the von Bertalanffy model. Additionally, total mortality (Z), natural mortality (M), fishing mortality (F), length at first capture (Lc), maximum yield per recruit (ERMY) and longevity were determined. Females were larger (3.07 ± 0.51 cm) than males (2.68 ± 0.25 cm) and dominant in the largest CL classes. The biometric relationships for males, females and both sexes grouped showed a negative allometric growth. Females showed larger L∞ (asymptotic length) and k (coefficient of growth) (L∞ of 5.00–5.16 cm and k of 1.20–1.26 year−1) when compared with males (L∞ of 4.25–4.30 cm and k of 1.00–1.02 year−1). In general, the mortality of males (Z = 1.93–5.48 year−1; M = 1.59–1.61 year−1 F = 0.32–0.3.89 year−1) and longevity (1.11–2.16 years) were higher than those estimated for females (Z = 1.84–3.76 year−1; M = 1.70–1.77 year−1; F = 0.07–1.99 year−1; 1.07–1.78 years). Results indicated that L. schmitti stock is relatively close to the state of full exploitation. Moreover, the CL of first capture of females (2.44–2.51 cm) is below the length of first sexual maturation of the species. The lack of legislation governing shrimp fishing in the area makes this stock even more vulnerable.

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.

Population structure of nurse sharks, Ginglymostoma cirratum (Orectolobiformes), caught off Ceará State, Brazil, south-western Equatorial Atlantic

2010 ◽  
Vol 91 (6) ◽  
pp. 1193-1196 ◽  
Author(s):  
Jones Santander-Neto ◽  
Renata A. Shinozaki-Mendes ◽  
Leonardo M. Silveira ◽  
Bruno Jucá-Queiroz ◽  
Manuel A.A. Furtado-Neto ◽  
...  
Keyword(s):  
Population Structure ◽  
Seasonal Pattern ◽  
Equatorial Atlantic ◽  
Nurse Shark ◽  
Female Ratio ◽  
Eastern Brazil ◽  
North Eastern ◽  
Ginglymostoma Cirratum ◽  
Male Female Ratio ◽  
Nurse Sharks

The nurse shark, Ginglymostoma cirratum, is considered an endangered species in Brazil and its capture by fisheries forbidden. Despite such legislation, nurse sharks continue to be caught as these laws are unenforced and fisheries are not monitored. The goal of the present study was to describe the population structure of nurse sharks caught off Ceará State, north-eastern Brazil, based on the following aspects: abundance and size, sex-ratio, fisheries incidence and seasonality of captures. Landings were monitored weekly during a two-year period. A total of 189 specimens were recorded. Total length (TL) varied between 73 and 274 cm. The male–female ratio did not differ significantly (1.19♀:1♂). TL of individuals landed as carcasses was estimated based on interdorsal length. The following equation was obtained for males and females: TL = 12.606ID + 14.24 (R2 = 0.9505). Most of the landed sharks were juveniles (86.2%). No seasonal pattern of abundance and TL variation was observed. Management of this fishery is required in order to prevent localized over-fishing of nurse sharks.

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