Scientia Marina, Vol 71, No 2 (2007)

Relative growth of the semi-terrestrial crab Pachygrapsus marmoratus: an information-theory approach

Nikos Prototapas
Department of Zoology-Marine Biology, Faculty of Biology, University of Athens , Greece

Stelios Katsanevakis
Department of Zoology-Marine Biology, Faculty of Biology, University of Athens , Greece

Maria Thessalou-Legaki
Department of Zoology-Marine Biology, Faculty of Biology, University of Athens , Greece

George Verriopoulos
Department of Zoology-Marine Biology, Faculty of Biology, University of Athens , Greece


The patterns of allometric growth of the grapsid crab Pachygrapsus marmoratus were investigated with an information-theoretic approach. This approach is beneficial, more robust, and may reveal more information than the classical approaches (e.g. hypothesis testing). No differentiation in allometric growth was detected between right and left chelar propods in either sex. Significant sexual differentiation in the allometric growth of chelar propods, abdominal somites and telson was found. It was shown that the allometry of chelar propodus width may be used to identify puberty in males, as there is a marked breakpoint at a carapace width of ~16.0 mm. For females, puberty was identified by the breakpoint in the allometry of the third and fourth abdominal somites at a carapace width of ~16.5 mm. In many cases (e.g. in chelar propods of males, or in most abdominal somites and the telson in females) the classic allometric equation log Y = log a + b log X has no essential support and non-linear allometric models between the log-transformed morphometric characters have to be used.


AIC; allometry; breakpoint; crab; growth; information-theory

Full Text:



Akaike, H. – 1973. Information theory and an extension of the maximum likelihood principle. In: B.N. Petrov and F. Csaki (eds.), Second international symposium on information theory, pp. 267-281. Akademiai Kiado, Budapest.

Akaike, H. – 1981. Likelihood of a model and information criteria. J. Econometrics, 16: 3-14 doi:10.1016/0304-4076(81)90071-3

Akaike, H. – 1983. Information measures and model selection. B. Int. Stat. Inst., 44: 277-291.

Buckland, S.T., K.P. Burnham and N.H. Augustin. – 1997. Model selection: an integral part of inference. Biometrics, 53: 603-618. doi:10.2307/2533961

Burnham, K.P. and D.R. Anderson. – 2002. Model selection and multimodel inference: a practical information-theoretic approach, 2nd edn. Springer, New York.

Cannicci, S., J. Paula and M. Vannini. – 1999. Activity pattern and spatial strategy in Pachygrapsus marmoratus (Decapoda: Grapsidae) from Mediterranean and Atlantic shores. Mar. Biol., 133: 429-435. doi:10.1007/s002270050481

Cannicci, S., M. Gomei, B. Boddi and M. Vannini. – 2002. Feeding habits and natural diet of the intertidal crab Pachygrapsus marmoratus: Opportunistic browser or selective feeder? Estuar. Coast. Shelf Sci., 54: 983-1001. doi:10.1006/ecss.2001.0869

Ebert, T.A. and M.P. Russell. – 1994. Allometry and Model II nonlinear regression. J. Theor. Biol., 168: 367-372. doi:10.1006/jtbi.1994.1116

Efron, B. and R.J. Tibshirani. – 1993. An introduction to the bootstrap. Chapman and Hall, New-York.

Flores, A. and J. Paula. – 2001. Intertidal distribution and species composition of brachyuran crabs at two rocky shores in Central Portugal. Hydrobiologia, 449: 171-177. doi:10.1023/A:1017573927565

Flores, A. and J. Paula. – 2002. Population dynamics of the shore crab Pachygrapsus marmoratus (Brachyura: Grapsidae) in the central Portuguese coast. J. Mar. Biol. Ass. U.K., 82: 229-241. doi:10.1017/S0025315402005404

Flores, A. and M.L. Negreiros-Fransozo. – 1999. Allometry of the socondary sexual characters of the shore crab Pachygrapsus transversus (Gibbes, 1850) (Brachyoura, Grapsidae). Crustaceana, 72: 1051-1066. doi:10.1163/156854099504013

Hall, N.G., K.D. Smith, S. de Lestang and I.C. Potter. – 2006. Does the largest chela of the males of three crab species undergo an allometric change that can be used to determine morphometric maturity? ICES J. Mar. Sci., 63: 140-150. doi:10.1016/j.icesjms.2005.07.007

Hartnoll, R.G. – 1963. The biology of Manx spider crabs. Proc. Zool. Soc. London, 141: 423-496.

Hartnoll, R.G. – 1983. Strategies of Crustacean Growth. Aus. Mus. Syd. Mem., 18: 121-131.

Hartnoll, R.G. – 1985. Growth, sexual maturity and reproductive output. In: A.M. Wenner (ed.), Crustacean issues 3, Factors in adult growth. Balkema, Rotterdam/Boston.

Hurvich, C.M and C.L. Tsai. – 1989. Regression and time series model selection in small samples. Biometrika, 76: 297-307. doi:10.1093/biomet/76.2.297

Huxley, J.S. – 1932. Problems of relative growth. Methuen, London.

Ingle, R.W. – 1980. British crabs. British Museum (Natural History), Oxford University Press, London.

Jolicoeur, P. – 1990. Bivariate allometry: interval estimation of the slopes of the ordinary and standardized major axes and structural relationship. J. Theor. Biol., 144: 275-285. doi:10.1016/S0022-5193(05)80326-1

Katsanevakis, S. – 2006. Modelling fish growth: model selection, multi-model inference and model selection uncertainty. Fish. Res., 81: 229-235. doi:10.1016/j.fishres.2006.07.002

Katsanevakis, S., M. Thessalou-Legaki, C. Karlou-Riga, E. Lefkaditou, E. Dimitriou and G. Verriopoulos. – 2007a. Information-theory approach to allometric growth of marine organisms. Mar. Biol., 151: 949-959. doi:10.1007/s00227-006-0529-4

Katsanevakis, S., J. Xanthopoulos, N. Protopapas and G.Verriopoulos. – 2007b. Oxygen consumption of the semi-terrestrial crab Pachygrapsus marmoratus in relation to body mass and temperature: an information theory approach. Mar. Biol., 151: 343-352. doi:10.1007/s00227-006-0485-z

McQuarrie, A.D.R. and C.L. Tsai. – 1998. Regression and time series model selection. World Scientific Publishing Company, Singapore.

Olmsted, J.M.D. and J.P. Baumberger. – 1923. A comparison of the form of three species of grapsoid crabs. J. Morphol., 38: 279-294. doi:10.1002/jmor.1050380203

Sainte-Marie, B. and G.A. Lovrich. – 1994. Delivery and storage of sperm at first mating of female Chionoecetes opilio (Brachyoura: Majidae) in relation to size and morphometric maturity of male parent. J. Crust. Biol., 14: 508-521. doi:10.2307/1548997

Shea, E.K. and M. Vecchione. – 2002. Quantification of ontogenetic discontinuities in three species of oegopsid squids using model II piecewise linear regression. Mar. Biol., 140: 971-979. doi:10.1007/s00227-001-0772-7

Somerton, D.A. – 1981. Regional variation in the size of maturity of two species of tanner crab (Chionoecetes bairdi and C. opilio) in the eastern Bering Sea, and its use in defining management subareas. Can. J. Fish. Aquat. Sci., 38: 163-174. doi:10.1139/f81-022

Somerton, D.A. – 1983. The size at sexual maturity of the blue king crab, Paralithodes platypus, in Alaska. Fish. Bull., 81: 621-628.

Tsuchida, S. and S. Watanabe. – 1997. Growth and reproduction of the grapsid crab Plagusia dentipes (Decapoda: Brachyoura). J Crust. Biol., 17: 90-97.

Vernet-Cornubert, C. – 1958. Recherches sur la sexualité du crab Pachygrapsus marmoratus (Fabricius). Arch. Zool. Exp. Gén., 96: 104-276.

Copyright (c) 2007 Consejo Superior de Investigaciones Científicas (CSIC)

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Contact us

Technical support