Croissance en longueur et en poids des perchaudes Perca flavescens de la Grande Anse de l'île Perrot au lac Saint-Louis

1972 ◽  
Vol 29 (5) ◽  
pp. 517-523 ◽  
Author(s):  
Réjean Fortin ◽  
Etienne Magnin

In this study, growth in length is based upon age determination on the opercular bones of 2170 specimens, collected throughout the year from June 1967 to October 1969. The opercular bone shows allometric growth and this is taken into account in back calculations. Grande Anse perch show comparatively rapid growth. Growth of males is slower than that of females. Seasonal growth extends from May to September. Faster growing fish reach sexual maturity earlier in life. Length–weight relationship exponent is 3.107. Due to the weight of the gonads, female perch show maximum condition index values in winter.

Author(s):  
Rosana Carina Flores Cardoso ◽  
Maria Lucia Negreiros-Fransozo

The allometric growth of Uca leptodactyla from two distinct subtropical estuaries on the Brazilian coast was evaluated concerning its growth pattern and size at onset of sexual maturity. Females attained maturity at similar sizes in both sites (4·1 mm of carapace length in Indaiá and 4·2 mm in Ubatumirim), while males differed slightly. They reached the size at sexual maturity of 5·3 mm of carapace length in Indaiá and 4·6 mm in Ubatumirim. Growth pattern is usually similar among crabs from distinct sites while size at sexual maturity is frequently different. However, in the case of U. leptodactyla it did not occur, probably due to the strong habitat similarity and intrinsic features of this species.


2020 ◽  
Vol 21 (8) ◽  
Author(s):  
AGUS INDARJO ◽  
Gazali Salim ◽  
MUFRIDA ZEIN ◽  
DODDY SEPTIAN ◽  
STEPHANIE BIJA

Abstract. Indarjo A, Salim G, Zein M, Septian D, Bija S. 2020. The population and mortality characteristics of mangrove crab (Scylla serrata) in the mangrove ecosystem of Tarakan City, Indonesia. Biodiversitas 21: 3856-3866. The mangrove crab is an iconic species of Tarakan City and is often is used as a souvenir. However, the high demand for this species can cause its population to decline. This study aimed to characterize the mangrove crab (Scylla serrata) population in the mangrove ecosystem of Tarakan City, North Kalimantan, Indonesia. This study was designed using a quantitative descriptive method with a case study model. The samples of mangrove crabs were obtained from 6 different stations using a purposive sampling method. The mangrove crab specimens were caught using 35-50 units of crab traps known as the ambau brackets. The primary data included carapace length, carapace width, carapace thickness, sex, and the total weight of each mangrove crab specimen. The results showed that male mangrove crabs have positive allometric growth when the condition index was fat. However, female crabs exhibited negative allometric growth when the condition index was thin. The Von Bertalanffy growth model analysis showed that the maximum carapace length of male mangrove crab in the mangrove ecosystem of Tarakan City was approximately 11.1118 cm for 189 days, while the female length was 9.6474 cm for 80 days. The total mortality value of male and female crabs was 120.01% and 154.94%, the mortality due to fishing was 84.69% and 135.75%, and natural mortality was 35.32% and 19.2%, respectively. The estimated rate of exploitation of both male and female crabs was 70.57% and 87.61%, respectively. The exploitation of S. serrata in the mangrove ecosystem of Tarakan City was evident, hence, conservation efforts are urgently required.


Author(s):  
Thomas Claverie ◽  
I. Philip Smith

Size at the onset of sexual maturity was determined in Munida rugosa based on allometric growth of chelipeds and abdomen, and on the proportion of ovigerous females. The variability of three different measurements of carapace length (CL) used previously for M. rugosa was also evaluated to minimize measurement error. Both sexes had symmetrical cheliped length and allometric cheliped growth over the size-range investigated, but males showed increased allometry beyond 22 mm CL. Females had greater positive allometry in abdomen width than males, but their size at maturity could not be precisely determined because sampled females were too large.


1979 ◽  
Vol 57 (8) ◽  
pp. 1649-1665 ◽  
Author(s):  
Jacques Castanet ◽  
Marc Cheylan

This work shows the value of osseous growth marks for age determination in two terrestrial chelonia, Testudo hermanni and Testudo graeca. Careful histological observation of long bones proves that concentric rings show a yearly growth pattern; we have already described similar findings in amphibians, snakes, and lizards.We confirm these data first by the observation of some wild turtles of known age and of a close correlation between the number of bone rings and the number of rings on the cornified scutes. We also confirm in both species that scutes have a yearly growth rhythm and we conclude that bone growth marks provide a good criterion for age determination. Resorption destroys some juvenile rings; we propose a calculation to evaluate the number of resorbed lines to obtain the true individual age.In our turtles, scute growth rings allowed age determination until sexual maturity. With osseous growth marks, we were able to extend accurate ageing until the 20th year. We also established that sexual maturity occurs when animals are 12 or 13 years old in both species, with little difference between males and females.


2009 ◽  
Vol 29 (3) ◽  
pp. 317-328 ◽  
Author(s):  
Sérgio Luizde Siqueira Bueno ◽  
Roberto Munehisa Shimizu

Author(s):  
Abdul-Razak M. Mohamed ◽  
Mohanad O. Al-Jubouri

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.


2015 ◽  
Vol 69 (4) ◽  
pp. 335-342 ◽  
Author(s):  
José Jonathas Pereira Rodrigues de Lira ◽  
Tereza Cristina dos Santos Calado ◽  
Carla Ferreira Rezende ◽  
José Roberto Feitosa Silva

1998 ◽  
Vol 25 (6) ◽  
pp. 635 ◽  
Author(s):  
P. M. Johnson

Reproduction of the whiptail wallaby, Macropus parryi, was studied in captivity. The mean length of the oestrous cycle was 41.8 days while the mean length of the gestation period was 38.0 days. M. parryi bred throughout the year and post-partum oestrus was not recorded although mating did occur during the pouch life when the pouch-young was 118–168 days of age. The length of the pouch-life was 256–267 days and weaning occurred 104–215 days after emergence from the pouch. Sexual maturity for females occurred at 509–647 days of age. An age-determination table was produced and found useful for predicting age of pouch-young using body measurements.


Nauplius ◽  
2016 ◽  
Vol 24 (0) ◽  
Author(s):  
Bruno Fernandes Takano ◽  
Felipe Pereira de Almeida Cohen ◽  
Adilson Fransozo ◽  
Roberto Munehisa Shimizu ◽  
Sérgio Luiz de Siqueira Bueno

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