Sympatry in grapsoid crabs (genera Planes and Plagusia) from olive ridley sea turtles (Lepidochelys olivacea), with descriptions of crab diets and masticatory structures

• Published in: Marine biology 2011-08, Vol.158 (8), p.1699-1708
• Main Authors: Frick, Michael G., Kopitsky, Kerry, Bolten, Alan B., Bjorndal, Karen A., Martins, Helen R.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Aquatic reptiles; Biological and medical sciences; Biomedical and Life Sciences; Crustacea; Crustaceans; Decapoda; Diet; Flotsam; Freshwater & Marine Ecology; Fundamental and applied biological sciences. Psychology; Invertebrates; Lepidochelys olivacea; Life Sciences; Marine; Marine & Freshwater Sciences; Marine biology; Microbiology; Morphology; Oceanography; Original Paper; Plagusia; Planes minutus; Reptiles & amphibians; Sea water ecosystems; Shellfish; Synecology; Teeth; Zoology
• ISSN: 0025-3162; 1432-1793
• DOI: 10.1007/s00227-011-1684-9

Grapsoid crabs of the genera Planes and Plagusia are commonly referred to as “rafting crabs” due to their propensity to live on flotsam and pelagic marine animals. Planes minutus and Planes major (= Planes cyaneus ) are epibionts of sea turtles. Occurrences of grapsoid crabs in the genera Planes and Plagusia were evaluated on a total of 27 olive ridley sea turtles, Lepidochelys olivacea , from the eastern tropic Pacific (1998–2001) and the Hawaiian Islands (2002) captured in July–December each year. This is the first report of Planes marinus and Plagusia squamosa on sea turtles, and of P . major , P . marinus , and P . squamosa in sympatry on a confined substrate. Stomach content analyses showed P . major and P . marinus consumed a variety of neuston and marine vegetation, with the former consuming considerably more animal material. Epibiotic P . squamosa consumed mostly plant material. The three Planes species had distinctive differences in gastric mill tooth morphology. The versatile mouthparts of P . marinus are described and resemble those of their congeners. Most female P . major and P . marinus collected were ovigerous and present in all survey months.