Relative growth, life-history phases, and sexual maturity of American lobster (Homarus americanus)

2010 ◽  
Vol 88 (4) ◽  
pp. 347-358 ◽  
Author(s):  
Kim Émond ◽  
Bernard Sainte-Marie ◽  
Louise Gendron
Keyword(s):  
Life History ◽  
Sexual Maturity ◽  
Body Part ◽  
Homarus Americanus ◽  
American Lobster ◽  
Body Parts ◽  
Growth Phases ◽  
Major Life ◽  
Relative Growth ◽  
Cephalothorax Length

Previous studies of relative growth in crustaceans have focused primarily on body parts representing sexual characters for the purpose of determining size at onset of sexual maturity. We have revisited the relative growth of abdomen and crusher claw in American lobster ( Homarus americanus H. Milne Edwards, 1837) in a general life-history perspective using a broad spectrum of lobster sizes (6–160 mm cephalothorax length (CL)). Growth phases were recognized by inflections in scatterplots of a body-part measurement against CL. The abdomen is characterized by three growth phases in the male and female, whereas the crusher claw has at least three growth phases in the male and at least two in the female. Additionally, we explored relative growth of gonopod and vas deferens for males of 35–150 mm CL. Both organs exhibit a synchronous change from strong to weak positive growth allometry. The growth phases can be associated with major life-history events including the transition from a cryptic to an overt lifestyle and the onset of physiological, functional, and morphometric maturity. The onset of morphometric maturation inferred from relative growth of abdomen and crusher claw precedes functional maturity in females and follows it in males.

Diffusion of American lobster (Homarus americanus) in Northumberland Strait, Canada

2009 ◽  
Vol 66 (4) ◽  
pp. 659-671 ◽  
Author(s):  
Cornelia Elizabeth den Heyer ◽  
E. Michael P. Chadwick ◽  
Jeffrey A. Hutchings
Keyword(s):  
Power Analysis ◽  
Sexual Maturity ◽  
Mean Square Displacement ◽  
Homarus Americanus ◽  
Small Sample ◽  
American Lobster ◽  
Fishing Gear ◽  
Positive Linear Correlation ◽  
Small Sample Sizes ◽  
Trawl Surveys

We tested the hypothesis that American lobster ( Homarus americanus ) movement can be described as diffusion. In 2001 and 2002, 3689 lobsters, captured by experimental trap and trawl surveys, were tagged and released in Northumberland Strait, Canada. Recaptures (n = 413) were reported by roughly 200 commercial fishermen, up to 3 years after release. Only six lobsters, all females, were recaptured more than once. Recapture rates were marginally higher for males (male 12%, female 10%) and varied with area of release (range: 5%–12%) and the fishing gear used for tagging (trap 12%, trawl 11%). Maximum and mean displacements between release and recapture were 58.3 and 12.3 km, respectively. The positive linear correlation between mean square displacement (MSD) and time between release and recapture provides evidence for diffusion. We calculate a diffusion coefficient (D) of 13 km2·week–1; there was no difference in D between sexes. A power analysis showed that MSD is underestimated at small sample sizes. There were insufficient data to test for differences in D associated with sexual maturity or shell hardness at time of release. During the summer in Northumberland Strait, the lobster population spreads about 20 km. The demographic consequences of seasonal diffusion of lobster warrant study.

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.

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).

Historical Review of Lobster Life History Terminology and Proposed Modifications To Current Schemes

Crustaceana ◽  
1996 ◽  
Vol 69 (5) ◽  
pp. 594-609 ◽  
Author(s):  
Peter Lawton ◽  
Kari L. Lavalli
Keyword(s):  
Life History ◽  
Size Range ◽  
Historical Review ◽  
Homarus Americanus ◽  
Behavioral Changes ◽  
American Lobster ◽  
Behavioral Attributes ◽  
Developmental Phases ◽  
The Impact ◽  
Current Terminology

AbstractTerms for the life history and developmental phases of the American lobster, Homarus americanus, vary substantially and have been frequently revised (Cobb et al., 1983; Hudon, 1987; Barshaw & Bryant-Rich, 1988; Wahle & Steneck, 1991; Cobb & Wahle, 1994). Their evolution shows several trends: (1) acknowledgement of pronounced morphological, physiological, and behavioral changes accompanying a metamorphic molt into the fourth pelagic stage; (2) recognition of behavioral changes (facilitated by decreasing mortality risk) leading to increased vagility over the size range ~ 5 to 40 mm carapace length (CL), and (3) consideration of the impact of reproductive maturation on lobster movement and social interaction. Before further modifying current terminological schemes (Wahle & Steneck, 1991; Cobb & Wahle, 1994), a historical perspective is provided and problems with existing schemes are presented. Our proposed scheme, which better integrates ecological ontogeny with developmental, biological, and individual behavioral attributes, partitions the life history into seven phases (exclusive of the attached egg and prelarval stages): pelagic larval, postlarval, shelter-restricted juvenile, emergent juvenile, vagile juvenile, adolescent, and adult. It should also provide a template from which to standardize life history schemes for spiny lobsters where there are similar problems with current terminology.

scholarly journals Relative growth, sexual maturity and handedness in the ghost shrimp Callichirus major (Decapoda: Callianassidae) from the southwestern Atlantic

2019 ◽  
Vol 83 (2) ◽  
pp. 167 ◽  
Author(s):  
Juliana Priscila Piva Rio ◽  
Patricio Hernáez ◽  
Marcelo Antonio Amaro Pinheiro
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Sexual Maturity ◽  
Adult Males ◽  
Allometric Growth ◽  
Growth Phases ◽  
Relative Growth ◽  
Ghost Shrimp ◽  
Living Organisms ◽  
Main Growth

Biometric studies provide valuable information about changes associated with the growth and sexual maturity of living organisms. We analysed sexual dimorphism, allometric growth, sexual maturity and handedness in the ghost shrimp Callichirus major at Gonzaga beach, Brazil, where the catches of this species have been prohibited since 1992. To this end, a total of 544 individuals of C. major were collected during 12 months of sampling. Males were significantly smaller than females, denoting sexual dimorphism with respect to body size. The analysis of allometric growth between chelar carpus length and carapace length (CL) revealed a positive allometric relationship in juveniles of both sexes and adult males, but a negative allometry in adult females. Overall, our results showed the existence of two main growth phases related to sexual maturity, with a similar transition point for males (15.0 mm CL) and females (16.0 mm CL). Heterochely and homochely were registered in shrimp from both sexes, but in males heterochely occurred to a higher degree and was predominant (86.9%), whereas in females homochely was slightly more frequent (59.3%). The consequences of sexual dimorphism in terms of body size and chelipeds in the mating system of C. major are discussed in this study.

scholarly journals Sex-Specific Routes to Independent Breeding in a Polygynous Cooperative Breeder

2021 ◽  
Vol 9 ◽  
Author(s):  
Dario Josi ◽  
Jana M. Flury ◽  
Maria Reyes-Contreras ◽  
Hirokazu Tanaka ◽  
Michael Taborsky ◽  
...  
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Sexual Maturity ◽  
Life History Strategies ◽  
Dominant Male ◽  
Dispersal Patterns ◽  
Major Life ◽  
Mating Patterns ◽  
Cooperatively Breeding ◽  
Fitness Benefits

How can individuals obtain a breeding position and what are the benefits associated with philopatry compared to dispersal? These questions are particularly intriguing in polygamous cooperative breeders, where dispersal strategies reflect major life history decisions, and routes to independent breeding may utterly differ between the sexes. We scrutinized sex-dependent life-history routes by investigating dispersal patterns, growth rates and mortality in a wild colony of the cooperatively breeding cichlid Neolamprologus savoryi. Our data reveal that female helpers typically obtain dominant breeding positions immediately after reaching sexual maturity, which is associated with strongly reduced growth. In contrast, males obtain breeder status only at twice the age of females. After reaching sexual maturity, males follow one of two strategies: (i) they may retain their subordinate status within the harem of a dominant male, which may provide protection against predators but involves costs by helping in territory maintenance, defence and brood care; or (ii) they may disperse and adopt a solitary status, which diminishes survival chances and apparently reflects a best-of-a-bad-job strategy, as there are no obvious compensating future fitness benefits associated with this pathway. Our study illustrates that sex-dependent life history strategies strongly relate to specific social structures and mating patterns, with important implications for growth rates, the age at which breeding status is obtained, and survival.

scholarly journals Relative growth and morphological sexual maturity of Chasmagnathus granulatus (Crustacea, Varunidae) from a mangrove area in southeastern Brazilian coast

2007 ◽  
Vol 97 (3) ◽  
pp. 268-272 ◽  
Author(s):  
Rafael Augusto Gregati ◽  
Maria Lucia Negreiros-Fransozo
Keyword(s):  
Sexual Maturity ◽  
Body Height ◽  
Allometric Equation ◽  
Brazilian Coast ◽  
Body Parts ◽  
Positive Allometry ◽  
Relative Growth ◽  
Males And Females ◽  
First Time ◽  
Chasmagnathus Granulatus

The relative growth and morphological sexual maturity of Chasmagnathus granulatus Dana, 1851 are presented for the first time to a mangrove population. The crabs were obtained during low tide periods, in the mangrove of Jabaquara Beach, Paraty, Rio de Janeiro, Brazil. All crabs in intermolt stage were sexed and had their body parts measured as follows: body height (BH), carapace length (CL) and width (CW), major cheliped propodus height (PH) and length (PL) for each sex, gonopod length (GL) and abdomen width (AW) for males and females, respectively. The relative growth was described using the allometric equation y=ax b and the size at onset sexual maturity was achieved using the software Mature I. The size of specimens ranged from 4.1 mm to 39.5 mm CW. The growth pattern was different between sexes in the cheliped relationships; the relationships BH vs. CW evidenced positive allometry for juveniles; PL vs. CW and PH vs. CW positive allometry for most crabs except juvenile females; AW vs. CW and GL vs. CW evidenced positive allometry for juveniles and isometry for adults. The relationships that best indicated the change from the juvenile to the adult phase were PH vs. CW for males and AW vs. CW for females. The size in which 50% of males from this population are mature is at 19.7 mm of CW (F=144.14; p<0.05) and for females it is at 19.2 mm of CW (F=166.54; p<0.05). The sizes obtained in this mangrove population are larger than those from previous studies, that could be attributed to a species plasticity concerning the habitat structure.

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