Patterns and processes of Chasmagnathus granulata and Cyrtograpsus angulatus (Brachyura: Grapsidae) recruitment in Mar Chiquita coastal lagoon, Argentina


Contact
ualexander [ at ] awi-bremerhaven.de

Abstract

Recruitment patterns of crabs and other benthic invertebrates with planktonic larvae are determined by a combination of pre- and post-settlement factors. Recruitment is considered settlement limited when there is a positive correlation between the postlarvae available in the water column and the number of recruits, and regulated when abundance of individuals is mainly affected by post-settlement factors, such as competence and inter or intraspecific predation. Temperate southwestern Atlantic saltmarshes are inhabited by Cyrtograpsus angulatus and Chasmagnathus granulata, two intertidal grapsid crabs. These crabs are considered key species in the ecosystem in Mar Chiquita coastal lagoon, Buenos Aires, Argentina. In this work, we compare the recruitment pattern of Cyrtograpsus angulatus and Chasmagnathus granulata on the basis of a 3-year sampling programme. Furthermore, we examine experimentally, in laboratory and field, settlement and postsettlement processes that can help explain these patterns: habitat selection, intra- and inter-cohort cannibalism and predator avoidance behaviour. Finally, we integrate our results with the previous knowledge about distribution, growth and reproductive biology of both species, to propose a model of recruitment of each species. Both species had a consistent recruitment pattern through 3 years. Recruitment of both species started at the beginning of summer, and continued to autumn, but recruits were present until the beginning of spring. Densities of recruits and juveniles of C. angulatus were not correlated, whereas, there was a relationship between abundance of recruits and juveniles of C. granulata. In the field, recruits of C. angulatus suffered high mortality caused by intra- and inter-cohort cannibalism. Megalopae of C. angulatus selected a substrate (crevices in Ficopomatus enigmaticus reef) that gave them refuge against cannibals. First crabs of C. granulata selected adult conspecific substrate (mud from adult habitats). Recruits of C. angulatus avoided adults of either species. A qualitative model of recruitment of both species is proposed. Post-settlement processes strongly affects the recruitment pattern and, consequently, both species have regulated recruitment. The degree of such regulation, however, is more intense in C. angulatus than in C. granulata.



Item Type
Article
Authors
Divisions
Programs
Peer revision
ISI/Scopus peer-reviewed
Publication Status
Published
Eprint ID
5223
DOI 10.1006/ecss.2001.0904

Cite as
Luppi, T. A. , Spivak, E. D. , Anger, K. and Valero, J. L. (2002): Patterns and processes of Chasmagnathus granulata and Cyrtograpsus angulatus (Brachyura: Grapsidae) recruitment in Mar Chiquita coastal lagoon, Argentina , ESTUARINE COASTAL AND SHELF SCIENCE, 55 , pp. 287-297 . doi: 10.1006/ecss.2001.0904


Download
[img]
Preview
PDF (Fulltext)
Lup2002a.pdf

Download (194kB) | Preview
Cite this document as:

Share


Citation

Research Platforms
N/A

Campaigns


Actions
Edit Item Edit Item