6 research outputs found
Selectivity curves of the capture of mangrove crab (Ucides cordatus) on the northern coast of Brazil using bayesian inference
Relação umidade versus resistência à penetração para um argissolo amarelo distrocoeso no recôncavo da Bahia
Fertilidade do caranguejo de mangue Ucides cordatus (Linnaeus) (Crustacea, Brachyura, Ocypodidae), em Iguape (São Paulo, Brasil) Fertility of the mangrove crab Ucides cordatus (Linnaeus) (Crustacea, Brachyura, Ocypodidae), at Iguape (São Paulo), Brazil
<abstract language="eng">A total of 58 Ucides cordatus (Linnaeus, 1763) ovigerous females in final embryonic stage were collected in mangrove forest at Iguape (São Paulo). Each female were kept in laboratory until the larvae hatching and had their carapace width (CW) measured with caliper (0.05 mm) and the larval number (LN) calculated by volumetric method. The hatching rates (HR) were calculated for each animal's size class (5 mm). The values of LN and CW obtained were subjected to regression analyses and the best fitting model was chosen by comparing the obtained determination coefficients (R²). The fertility varied from 71,200 to 220,800 larvae (147,169 ± 32,070 larvae), corresponding to 41.7 to 76.8 mm CW (63.7±7.9 mm), respectively. The relationship LNxCW was expressed by the equation LN = 284.1CW1.5º¹ (N = 58; R² = 0.74; p < 0.01), that showed a positive correlation between the variables. Most part of ovigerous females (89.7%) showed their hatching during the nightly period. A negative correlation between HR and CW was observed in these animals (p < 0.05), probably due to reduction of spermatophores in the seminal receptacle (multiparous females) or due to senility in the females with large size. The biological studies of U. cordatus are very important for practices adoption that preserve and make the rational use of this recourse in Brazilian's mangrove forests
Maturation and growth curves of Macrobrachium Carcinus (Linnaeus) (Crustacea, Decapoda, Palaemonidae) from Ribeira de Iguape River, southern Brazil
In this paper, female Macrobrachium carcinus (Linnaeus, 1758) maturation curve, weight/length relationship, length and weight growth curves were studied. Prawns were captured, by traps, in Ribeira de Iguape river (24ºS and 47ºW), southern Brazil. There were used 207 females. It was observed that M. carcinus presents several spawnings during its life cycle and reproductive period goes on, at least till six years old. Weight/length relationship can be represented for the equation W = 8.73 E-3 L3.28. Expressions obtained for length and weight growth curves are Lt = 21 .0 (1-e-0493t) and Wt= 190 (1-e-0493t)3.28. respectively. A symptotic maximum length and asymptotic maximum weight are nearly attained at six and eight years old, respectively