scholarly journals Relative growth and reproduction in Achelous spinicarpus (Crustacea: Portunidae) on the south-eastern continental shelf of Brazil

2012 ◽  
Vol 93 (3) ◽  
pp. 667-674 ◽  
Author(s):  
André L. Pardal-Souza ◽  
Marcelo A.A. Pinheiro
Keyword(s):  
Continental Shelf ◽  
Sexual Maturity ◽  
Developmental Stages ◽  
Carapace Width ◽  
Gravimetric Method ◽  
Tropical Region ◽  
The South ◽  
Relative Growth ◽  
South Eastern ◽  
Size At Sexual Maturity

This investigation aimed to study the relative growth, morphological sexual maturity and fecundity of the swimming crab Achelous spinicarpus in a tropical region, on the south-eastern continental shelf of Brazil (25°S). Biometry of all specimens was conducted, including measurements of the cephalothorax, cheliped, abdomen and gonopods. Relative growth was described based on the equation for allometry (y = axb), and size at sexual maturity was determined from inflections in relations involving the cheliped, gonopods (males), and abdomen (females), as dependent variables, related to the cephalothorax width (independent variable). Fecundity was estimated by the gravimetric method. The relations of the length of the chelar propodus and carpal spine to the carapace width without the lateral spines (CW) showed positive allometry in both sexes, with a significant variation in the constant ‘b’ for males between the developmental stages (juvenile and adult) and the size at maturity estimated at 37 mm CW. In females, the abdomen was most appropriate for the estimate of morphological maturity, which occurred at a smaller size (32 mm CW), with a change in the growth pattern between the stages, passing from isometric (juveniles) to positive allometric (adults). The gonopods also showed different growth rates between developmental stages, in synchrony with the variables of the cheliped. Mean fecundity for the species was 53,984 eggs, with a positive correlation between the number of eggs exteriorized and the size of the female; the equations allowed interconversion between these variables, due to the adjustment of the power function (r2 ≥ 86%).

scholarly journals Size at sexual maturity of female crabs Sesarma rectum Randall (Crustacea, Brachyura) and ontogenetic variations in the abdomen relative growth

2005 ◽  
Vol 22 (2) ◽  
pp. 433-437 ◽  
Author(s):  
Maria H. de A. Leme
Keyword(s):  
Sexual Maturity ◽  
Carapace Width ◽  
Analysis Of Covariance ◽  
Northern Coast ◽  
Growth Phases ◽  
Differential Growth ◽  
Relative Growth ◽  
Gonadal Maturity ◽  
Body Sizes ◽  
Size At Sexual Maturity

The aim of the present study was to ascertain the size at sexual maturity in females of the crab Sesarma rectum Randall, 1840 by comparing gonadal maturity to morphologic maturity (using abdomen-width data). The relative growth of the abdomen was analysed for all growth phases (for each 3-mm carapace width size class), and the slopes of the separate allometric relationships were compared through analysis of covariance (ANCOVA) from log e-transformed data to detect changes in the level of allometry during ontogeny. The physiological size at maturity (gonadal criteria) was determined through a logistic curve, indicating the size at which 50% of females presented mature gonads (M50 = 17.4 mm CW). The highest allometric levels occurred in growth phases 2 and 3 (body sizes ranging from 15 to 21 mm CW), indicating faster growth of the abdomen during those phases. Phases 1 (< 15 mm CW) and 4 and 5 (size classes above 21 mm CW) showed isometric growth. In the study area, a mangrove on the northern coast of the state of São Paulo, Brazil, individuals of S. rectum began to reach sexual maturity from 15 mm CW onward, when the slopes of the relationship of abdomen width to carapace width became positively allometric, indicating a differential growth rate. A gradual decrease in the slope, tending to isometry, occurred during ontogeny, as the animals became larger (older).

scholarly journals Relative growth and sexual maturity of the stone crab Menippe nodifrons Stimpson, 1859 (Brachyura, Xanthoidea) in southeastern Brazil

2007 ◽  
Vol 50 (2) ◽  
pp. 259-267 ◽  
Author(s):  
Giovana Bertini ◽  
Adriane Araújo Braga ◽  
Adilson Fransozo ◽  
Michéle de Oliveira Dias Alves Corrêa ◽  
Fulvio Aurélio de Morais Freire
Keyword(s):  
Sexual Maturity ◽  
Carapace Width ◽  
Southeastern Brazil ◽  
Positive Allometry ◽  
Relative Growth ◽  
Stone Crab

The relative growth and size at onset of morphological sexual maturity of the stone crab Menippe nodifrons were investigated. A total of 399 crabs was captured on Praia Grande and Tenório beaches at Ubatuba. Carapace width (CW) and length, cheliped propodus length and height, abdomen width in females, and gonopod length in males were recorded. In females, the abdominal width showed negative allometry for juveniles and positive allometry for adults; the puberty molt occurred at 31.6 mm CW. In males, the size at onset of morphological sexual maturity was estimated as 29.7 mm CW; the gonopod growth showed positive allometry for juveniles, and an isometric relationship for adults. The gonopod length and the abdominal width were the most appropriate morphometric variables to estimate size at onset of sexual maturity in this stone crab.

scholarly journals The relative growth and sexual maturity of the freshwater crab Dilocarcinus pagei (Brachyura, Trichodactylidae) in the northwestern region of the state of São Paulo

2013 ◽  
Vol 103 (3) ◽  
pp. 232-239 ◽  
Author(s):  
Daphine R. Herrera ◽  
Thiago M. Davanso ◽  
Rogerio C. Costa ◽  
Fabiano G. Taddei
Keyword(s):  
Sexual Maturity ◽  
Sao Paulo ◽  
Minimum Size ◽  
São Paulo ◽  
Freshwater Crab ◽  
Relative Growth ◽  
Stage Of Development ◽  
Gonadal Maturity ◽  
Size At Sexual Maturity ◽  
Dilocarcinus Pagei

The aim of the present study was to determine the size at sexual maturity in the freshwater crab Dilocarcinus pagei Stimpson, 1861, from a population located in Mendonça, state of São Paulo, Brazil. The crabs were sampled monthly (July 2005 to June 2007), at Barra Mansa reservoir. The specimens were captured manually or in sieves passed through the aquatic vegetation. The crabs were captured and separated by sex based on morphology of the pleon and on the number of pleopods. The following dimensions were measured: carapace width (CW); carapace length (CL); propodus length (PL); and abdomen width (AW). The morphological analysis of the gonads was used to identify and categorize individuals according to their stage of development. The morphological maturity was estimated based on the analysis of relative growth based on the allometric equation y = ax b. The gonadal maturity was based on the morphology of the gonads by the method CW50 which indicates the size at which 50% of the individuals in the population showed gonads morphologically mature to reproduction. The biometric relationships that best demonstrated the different patterns of growth for the juvenile and adult stages were CW vs. PL for males and CW vs. AW for females (p<0.001). Based on these relationships, the estimated value to morphological sexual maturity was 21.5 mm (CW) in males and 19.7 mm (CW) in females. The determination of the size at sexual maturity and the adjustment of the data based on the logistic curve (CW50) resulted in a size of 38.2 mm for males and 39.4 mm for females (CW). Based on the data obtained for sexual maturity for D. pagei, we can estimate a minimum size for capture of 40 mm (CW). This minimum size allows at least half of the population to reproduce and retains the juveniles and a portion of the adults in the population.

Size at maturity of Liocarcinus depurator (Brachyura: Portunidae): a reproductive and morphometric study

1999 ◽  
Vol 79 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Rámon Muiño ◽  
Luis Fernández ◽  
Eduardo González-Gurriarán ◽  
Juan Freire ◽  
José A. Vilar
Keyword(s):  
Sexual Maturity ◽  
Carapace Width ◽  
Principal Component ◽  
Morphometric Study ◽  
Gonad Maturation ◽  
Body Parts ◽  
Size At Maturity ◽  
Two Phase ◽  
Morphometric Variation ◽  
Relative Growth

Sexual maturity in brachyurans is often associated with an allometric change in the relative growth of the animal. Maturity of Liocarcinus depurator was examined by analysing the monthly percentages of mature females (determined by the stage of gonad maturation and the presence of brood and sperm plugs) by size-class and the relative growth of different body parts: length and width of the carapace, length, height and width of the cheliped propodus; width of the abdominal segments in females and length of the first pleopod in males. Using the reproductive criteria the size at the onset of sexual maturity (carapace width at which 50% females are mature) in females of L. depurator is around 30–34 mm cephalothorax width. Principal component analysis (PCA) showed that the main source of morphometric variation for both sexes was due to heterochelia and allometric changes in growth. Morphometric variables were fitted using different regression techniques to one and two-phase growth models. The length of the first pleopod and the propodus of the right cheliped in males, and width of abdominal segments in females showed two clearly differentiated phases. Estimated maturity size (carapace width) corresponding to 50% mature animals was greater in males than in females. In males, size at the onset of maturity ranged between 31.4 and 35.7 mm, depending on the methods and variables used. The size at the onset of maturity in females ranged between 25.5 and 31.5 mm. In the Ría de Arousa, the size at maturity in females of L. depurator estimated using reproductive criteria is considerably greater than the size found based on morphometric criteria. The size at maturity based on morphometric criteria is greater in males than in females.

Delineating fish-habitat associations for spatially based management: an example from the south-eastern Australian continental shelf

2001 ◽  
Vol 52 (4) ◽  
pp. 513 ◽  
Author(s):  
Alan Williams ◽  
Nicholas J. Bax
Keyword(s):  
Community Structure ◽  
Continental Shelf ◽  
Fish Habitat ◽  
Habitat Associations ◽  
The South ◽  
Community Patterns ◽  
Habitat Features ◽  
South Eastern ◽  
North East ◽  
Representative System

A multi-scale, multi-gear survey identified the spatial structure and compositions of fish communities from a range of seabed types on the south-eastern Australian continental shelf (25 m to ~200 m depth). Most communities are species-rich and contain many shared species. Multivariate analysis of distributions of 201 fishes showed communities to be correlated with depth, latitude and seabed type;correlation with hydrodynamic climate is suggested by patterns in morphology. Depth-related patterns occurred on soft-sediment and hard substrata; strong latitudinal (south-west/north-east)patterns identify the area as a faunal transition zone with a major faunal disjunction extending across the shelf. Community patterns were overlaid on distributions of substrata to produce a biophysical map. This mapping process is discussed in the context of spatial management:the ecologically significant scale at which to map habitat features and definition of management units for ecosystem-based management. A hierarchy of scaled ecological units is being developed for Australia’s National Representative System of Marine Protected Areas (NRSMPA);given the scope of the NRSMPA initiative, surrogate measures of community structure will be required. Maps of substrata and topography, interpreted in the context of the broader depth and latitudinal community structure and as modified by hydrography, may provide one useful surrogate.

Distribution and Dispersal of the Phyllosoma Larvae of the Western rock Lobster, Panulirus cygnus, in the South-eastern Indian Ocean

1979 ◽  
Vol 30 (6) ◽  
pp. 773 ◽  
Author(s):  
BF Phillips ◽  
PA Brown ◽  
DW Rimmer ◽  
DD Reid
Keyword(s):  
Indian Ocean ◽  
Continental Shelf ◽  
Average Length ◽  
Eastern Indian Ocean ◽  
Rock Lobster ◽  
The South ◽  
South Eastern ◽  
Phyllosoma Larvae ◽  
Panulirus Cygnus ◽  
One Year

Data on the phyllosoma larvae of P. cygnus caught on seven cruises carried out between April 1976 and January 1977 off the west coast of Australia are presented and discussed. The studies were undertaken to determine the length of the plankton cycle, the distribution of the phyllosoma in the south-eastern Indian Ocean and the extent of the offshore dispersal. Analyses showed the average length of the planktonic life to be less than one year and probably between 9 and 11 months. After hatching most early phyllosoma were transported offshore. Few larvae remained on or near the continental shelf. The maximum westward extent of the phyllosoma distribution of P. cygnus was not determined because significant numbers of phyllosoma were still found as far offshore as 99� 001E. (1500 km offshore), the furthest station sampled. The phyllosoma were distributed over an extensive area of the south-eastern Indian Ocean, and there were few stations beyond the continental shelf between 24� 30'S. and 35� 00'S., from 99� 00'E. to 115� 00'E., during midwinter, at which phyllosoma were not caught. The highest densities of mid-and late-stage phyllosoma occurred between 111� 00' E. and 104� 00' E. (between 375 and 1030 km offshore), at 29� 30'S. The area of greatest abundance was due west of the approximate centre of the adult distribution on the coast. The significance of the circulation of the south-eastern Indian Ocean in the transport of the larvae is discussed.

scholarly journals Morphological variability in populations of the fiddler crab Leptuca uruguayensis (Nobili, 1901) (Crustacea, Decapoda, Ocypodidae) from South America

2017 ◽  
Vol 65 (3) ◽  
pp. 373-381 ◽  
Author(s):  
Setuko Masunari ◽  
Salise Brandt Martins ◽  
Murilo Zanetti Marochi ◽  
Wilson Sebastián Serra ◽  
Fabrizio Scarabino
Keyword(s):  
Posterior Margin ◽  
Sexual Maturity ◽  
Growth Analysis ◽  
Fiddler Crab ◽  
Carapace Width ◽  
Morphological Variability ◽  
Centroid Size ◽  
Relative Growth ◽  
Abiotic Variables ◽  
Major Cheliped

Abstract A comparative study on size and shape of Leptuca uruguayensis was carried out between populations from Garças River, Brazil (BP), and Solís Grande River, Uruguay (UP). The size of the onset of sexual maturity was also estimated for UP. A total of 36 crabs BP and 387 crabs UP were analyzed. In the relative growth analysis, carapace width (CW) for both sexes, major cheliped length (LMC) for males and abdomen width (AW) for females were measured. The centroid size of carapace (1.40±0.19 cm BP and 1.88±0.30 cm UP) and cheliped (1.16±0.22 cm BP and 1.58±0.45 cm UP) differed significantly (p<0.001). The shape also differed significantly (p<0.001), having UP wider carapace than BP, rostrum projected forward and posterior margin positioned more anteriorly; the cheliped of UP was also wider than BP. In UP, males' CW ranged 4.28-19.5 mm and females' 2.53-16.3 mm CW; males' LMC ranged 1.79-31.60 mm and females' AW, 0.80-8.53 mm. The onset of sexual maturity of UP was estimated in 12.20 mm CW for males and 7.81 mm for females. These differences are likely related to abiotic variables acting distinctly in the two localities.

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