Morphological maturity and allometric growth in the squat lobster Munida rugosa

2009 ◽  
Vol 89 (6) ◽  
pp. 1189-1194 ◽  
Author(s):  
Thomas Claverie ◽  
I. Philip Smith
Keyword(s):  
Measurement Error ◽  
Sexual Maturity ◽  
Carapace Length ◽  
Size Range ◽  
Size At Maturity ◽  
Allometric Growth ◽  
Positive Allometry ◽  
Squat Lobster

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.

scholarly journals A comparison of the allometric growth in Uca leptodactyla (Crustacea: Brachyura: Ocypodidae) from two subtropical estuaries

2004 ◽  
Vol 84 (4) ◽  
pp. 733-735 ◽  
Author(s):  
Rosana Carina Flores Cardoso ◽  
Maria Lucia Negreiros-Fransozo
Keyword(s):  
Growth Pattern ◽  
Sexual Maturity ◽  
Carapace Length ◽  
Brazilian Coast ◽  
Allometric Growth ◽  
Size At Sexual Maturity ◽  
Subtropical Estuaries ◽  
Habitat Similarity

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.

scholarly journals Comparative analysis of the relative growth of Uca rapax (Smith) (Crustacea, Ocypodidae) from two mangroves in São Paulo, Brazil

2004 ◽  
Vol 21 (1) ◽  
pp. 137-144 ◽  
Author(s):  
Daniela da Silva Castiglioni ◽  
Maria Lucia Negreiros-Fransozo
Keyword(s):  
Comparative Analysis ◽  
Sexual Maturity ◽  
Carapace Width ◽  
Reproductive Behaviour ◽  
Size At Maturity ◽  
Allometric Growth ◽  
Relative Growth ◽  
Males And Females ◽  
Two Populations ◽  
Major Cheliped

A study on the relative growth of two populations of Uca rapax (Smith, 1870) was performed primarily to determine the size at onset sexual maturity. The species was sampled monthly in Itamambuca (23º24'43"S and 45º00'73"W) and Ubatumirim (23º20'17.8"S and 44º53'2.2"W) mangroves. Carapace width (CW) and length (CL), abdomen width (AW), major cheliped propodus length (PL) and height (PH) for each sex, and gonopod length (GL) for males were measured with a calliper (0.01 mm). Allometric analyses were used to estimate size at maturity. The relationships that most precisely indicated the size at onset of sexual maturity were AW vs. CW, for females and PL vs. CW, for males. Males and females are mature, respectively at 15.2 and 12.1 mm CW in samples from Itamambuca and 13.5 and 11.2 mm CW in samples from Ubatumirim mangrove. Positive allometric growth of females abdominal width is likely related to the incubation process, while positively allometry growth of male's cheliped almost certainly relates to reproductive behaviour.

Size–Maturity Relationships and Related Observations in Newfoundland Populations of the Lobster (Homarus americanus)

1980 ◽  
Vol 37 (6) ◽  
pp. 945-956 ◽  
Author(s):  
G. P. Ennis
Keyword(s):  
Carapace Length ◽  
Size Range ◽  
Sex Ratios ◽  
Weight Ratio ◽  
Homarus Americanus ◽  
Spawning Season ◽  
Length Ratio ◽  
Maturity Indices

Female maturity ogives for five Newfoundland populations of the lobster (Homarus americanus) gave 50% maturities ranging from 71- to 76-mm carapace length. Sizes at which distinct inflections (indicating onset of maturity) and asymptotes (indicating 100% mature) are present in the abdomen width/carapace length ratio vs. carapace length relationships coincide with the smallest ovigerous and largest immature specimens, respectively, observed in those particular samples. Inflection in the crusher claw weight/whole weight ratio vs. carapace length relationships (used in this paper to indicate onset of maturity in males) occurred at larger sizes than inflections in the abdomen width/carapace length ratios of females.The percentage of nonovigerous females that spawn in a given year generally increases with increasing size. The highest percentage of nonovigerous females tagged with sphyrion tags prior to the spawning season that were ovigerous when recaptured 10–12 mo later was 83.8%. The percentage of ovigerous females with new shells (i.e. molted and spawned in same year) varied between areas and years and ranged from 0 to 38.5% of the total number of ovigerous females in fall samples. The percentage of ovigerous females in samples also varied between areas and years and ranged from 2.6 to 30.4% of the total number of females greater than the size at 50% maturity. In general a greater percentage of females was ovigerous at sizes between the size at 50% maturity and 80 mm (largest subcommercial size) than at commercial sizes.In a sample of nonovigerous females, the size range at which 50% were fertilized (76–80 mm) coincided closely with the size at 50% maturity (75 mm) for the area.At subcommercial sizes (< 81 mm) the sexes were approximately equally represented in fall trap-caught samples but females heavily outnumbered males in diver-caught samples taken over the same period. At commercial sizes, however, males heavily outnumbered females in the trap-caught samples while in diver-caught samples the sexes were equally represented.Key words: lobster (Homarus americanus), maturity ogives, maturity indices, percent ovigerous, sex ratios

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 population and mortality characteristics of mangrove crab (Scylla serrata) in the mangrove ecosystem of Tarakan City, Indonesia

2020 ◽  
Vol 21 (8) ◽  
Author(s):  
AGUS INDARJO ◽  
Gazali Salim ◽  
MUFRIDA ZEIN ◽  
DODDY SEPTIAN ◽  
STEPHANIE BIJA
Keyword(s):  
Carapace Length ◽  
Total Mortality ◽  
Condition Index ◽  
Mangrove Ecosystem ◽  
Scylla Serrata ◽  
Primary Data ◽  
Allometric Growth ◽  
Male And Female ◽  
Mangrove Crab ◽  
Mangrove Crabs

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.

Biennial Reproductive Cycle of Blue King Crab, Paralithodes platypus, at the Pribilof Island, Alaska and Comparison to a Congener, P. camtschatica

1989 ◽  
Vol 46 (6) ◽  
pp. 932-940 ◽  
Author(s):  
Gregory C. Jensen ◽  
David A. Armstrong
Keyword(s):  
Carapace Length ◽  
Reproductive Output ◽  
Size Range ◽  
Egg Mass ◽  
King Crab ◽  
Pribilof Island ◽  
Blue King Crab ◽  
Paralithodes Platypus ◽  
One Year ◽  
Reproductive Events

Pribilof Island blue king crab (BKC; Paralithodes platypus) were sampled by beam trawl in May and August of 1983 and April 1984 to determine timing of reproductive events. Biennial reproduction was found to be the result of slow ovarian growth in large, muciparous females, while smaller primiparous females are often able to spawn in two consecutive years. Mating and egg extrusion occur in late March to early May and eggs hatch in mid-April of the following year, consequently, the embryonic period and rate of development is approximately 12 mo, similar to that of its congener the red king crab (RKC; P. camtschatica). Comparison of the reproductive output of the two species revealed that despite the 2 yr ovarian cycle, BKC only produce 20–30% more dry egg mass at any carapace length than do RKC, a substantially smaller difference than previously calculated. One year after molt, females of both species are not significantly different in dry body weight over a size range of 100–140 mm carapace length, but RKC have produced about three times more dry ovarian weight than BKC of comparable size, suggesting that biennial reproduction in BKC may be the result of energetic limitations.

ALLOMETRY OF THE SECONDARY SEXUAL CHARACTERS OF THE SHORE CRAB PACHYGRAPSUS TRANSVERSUS (GIBBES, 1850) (BRACHYURA, GRAPSIDAE)

Crustaceana ◽  
1999 ◽  
Vol 72 (9) ◽  
pp. 1051-1066 ◽  
Author(s):  
Maria Lucia Negreiros-Fransozo ◽  
Augusto Flores
Keyword(s):  
Growth Phase ◽  
Carapace Length ◽  
Shore Crab ◽  
Female Size ◽  
Allometric Growth ◽  
Secondary Sexual Characters ◽  
Size At Sexual Maturity ◽  
Reproductive Females ◽  
Crab Stage ◽  
Secondary Sexual

AbstractThe allometric growth of secondary sexual characters in Pachygrapsus transversus is investigated from the 2nd crab stage onward. Clear sexual dimorphism is restricted to abdominal morphology, but ANCOVA analyses showed that chelae become larger in males and the carapace becomes wider in females. Size at the puberty moult in both sexes was estimated using Somerton's computer techniques. Mature II analyses applied to bi-log gonopod length vs. carapace length relationships indicated a puberty moult at 5.0 mm in males. In females, Mature I analyses detected the overlapping growth phase lines in bi-log carapace length vs. abdomen width scatterplots. Fitting the logistic equation provided an estimate of 50% maturity at 5.5 mm. The regression lines separate young and resting individuals from the potentially reproductive females, but they do not separate young from adult crabs. Year-round monthly samples showed that the proportion of small adult-like females is higher during the breeding season. After breeding, females may moult to a young-like morphotype, as observed in controlled laboratory conditions. Moulting to a resting condition splits smaller mature females into different "growth phase" lines. Therefore, estimates of female size at sexual maturity by means of abdomen allometric growth analyses are inadequate in this species. El crecimiento alometrico de los caracteres sexuales secundarios de Pachygrapsus transversus ha sido investigado desde el segundo estadio pos-larval. El dimorfismo abdominal es la unica caracterostica que permite distinguir claramente los sexos, pero los analisis de covarianza aplicados a las regresiones obtenidas demuestran que las quelas se vuelven m as grandes en machos y que el caparazon se vuelve mas ancho en hembras. La talla en que ambos sexos alcanzan la maturidad sexual ha sido estimada atraves de las tecnicas de Somerton. La aplicacion del programa Mature II a la regresion bi-log entre el largo del caparazon y el largo del gonopodo indica que la muda de la pubertad de los machos ocurre a los 5,0 mm. En las hembras, el programa Mature I detecto la sobreposicion de loneas de regresi on en los diagramas de dispersion de la regresion bi-log entre el largo del caparazon y el ancho del abdomen. Del ajuste de la ecuacion logostica se obtiene que 50% de las hembras son sexualmente adultas a los 5,5 mm. Estas rectas de regresion separan las hembras con potencial reproductivo de los indivoduos j ovenes y aquellos en reposo sexual. Sin embargo, las rectas no separan jovenes de adultos. Muestreos mensuales a lo largo de un ano indican que la proporcion de hembras de talla puberal con morfologia adulta es mas elevada durante el peroodo reproductivo. Despues de la reproduccion, estas hembras pueden obtener en la siguiente muda una condicion morfologica semejante a la joven, como fue verificado en condiciones de laboratorio controladas. La obtencion del reposo sexual divide a las hembras de talla puberal en rectas de regresion distintas, por lo que las estimativas de talla a la maturidad sexual atraves del analisis del crecimiento alometrico del abdomen son inadequadas para esta especie.

Changes in female lobster (Homarus americanus) size at maturity and implications for the lobster resource in Long Island Sound, Connecticut

2001 ◽  
Vol 52 (8) ◽  
pp. 1283 ◽  
Author(s):  
Donald F. Landers Jr ◽  
Milan Keser ◽  
Saul B. Saila
Keyword(s):  
Sexual Maturity ◽  
Egg Production ◽  
Long Island ◽  
Homarus Americanus ◽  
Long Island Sound ◽  
Female Size ◽  
Size At Maturity ◽  
Size At Sexual Maturity ◽  
Average Size ◽  
Island Sound

Population theory predicts that, under conditions of high age/size-specific mortality rates, individuals in highly exploited populations increase their fitness by decreasing size at sexual maturity, relative to less exploited populations. The benefit of early reproductive maturation is that individuals have a higher probability of surviving to maturity and contributing progeny to maintain the population. Empirical evidence, based on morphometric data from nearly 60 000 female lobsters collected since 1981, suggests that size at sexual maturity of female lobsters in Long Island Sound (USA) has recently decreased. Our findings were supported by decreases in average size and increases in abundance of egg-bearing females over the past two decades. Changes in female size at maturity and subsequent higher egg production may also help to explain the recent increase in lobster recruitment and landings. It is unclear whether these changes were caused by density-dependent factors related to the high exploitation of the species, by natural environmental factors (e.g. higher seawater temperatures), or a combination of the two.

Biological tags as moult indicators in Panulirus cygnus (George)

1997 ◽  
Vol 48 (8) ◽  
pp. 959 ◽  
Author(s):  
R. Melville-Smith ◽  
J. B. Jones ◽  
R. S. Brown
Keyword(s):  
Carapace Length ◽  
Size Range ◽  
Field Trials ◽  
Size Category ◽  
Fishing Season ◽  
Panulirus Cygnus ◽  
Biological Tags

Laboratory and field trials were employed to examine the feasibility of using biological tags as moult indicators. Twenty-four animals were tagged with epidermal implants and held in aquaria for 2 years and 8 months before the tags were removed. Five tags failed to form useful cysts and one tag was damaged during processing. The remaining 18 lobsters moulted between three and six times, with this moulting record being accurately verified by 15 of the biological tags and incorrectly interpreted (by one moult) in one case. Two tags produced inconclusive results. Biological tags were tested in the field in the Fremantle area, with 132 animals being recaptured out of 1336 tagged. Eleven tags proved impossible to read, eight failed to form cysts, and the balance recorded up to six moults during the release period. Animals in the size range 60–80 mm carapace length (CL) recorded two moults per year, one in February–April and a second before the mid-November start to the fishing season. Females grew significantly less per moult than did males in the same size category (60–85 mm CL), and both sexes showed significantly smaller increments for animals ≥85 mm CL at release.

Integrated analysis of sexual maturation through successive growth instars in the spider crab Leurocyclus tuberculosus (Decapoda: Majoidea)

2017 ◽  
Vol 95 (7) ◽  
pp. 473-483 ◽  
Author(s):  
Ximena González-Pisani ◽  
Pedro J. Barón ◽  
Laura S. López Greco
Keyword(s):  
Sexual Maturation ◽  
Sexual Maturity ◽  
Carapace Width ◽  
Integrated Analysis ◽  
Growth Stages ◽  
Spider Crab ◽  
Size At Maturity ◽  
Frequency Distributions ◽  
The Right ◽  
Sexually Mature

An integrative analysis of sexual maturity associated with growth was developed for the spider crab Leurocyclus tuberculosus (H. Milne Edwards and Lucas, 1842). Sexual maturity was characterized based on gonadal, morphological, morphometric, and functional sexual maturity. Progress in sexual maturation was described through 13 growth stages (instars) detected by the examination of size (carapace width) frequency distributions. Mature females displayed mature ovaries, developed vaginae, open gonopores, allometric changes in the abdomen, and ovigerous stage in the transition from instar IX to instar X. Sexually mature males presented spermatophores in the distal vasa deferentia and allometric changes in several measurements of the right chela in the transition from instar X to instar XI. However, two prepubertal phases were recognized in both sexes separated from each other by a prepubertal critical molt. Preceding the second critical molt, gonopores were sealed and vasa deferentia showed no spermatophores, and therefore neither sex was able to mate. The integrated analysis of size at maturity and size frequency distributions showed that in both sexes molt to gonadal, morphological, morphometric, and functional sexual maturity occurred in advance of the terminal molt, in contrast with patterns observed in other Majoidea.

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