, Volume 101, Issue 1, pp 17–38 | Cite as

Functional morphology of the mouthparts and associated structures of Pagurus rubricatus (Crustacea: Decapoda: Anomura) with special reference to feeding and grooming

  • Patrick J. Schembri


Pagurus rubricatus is predatory, detrivorous, macrophagous, and to a small degree, a suspension feeder. The crab searches for small invertebrates by digging shallow pits in the sediment. During this process it feeds on detritus obtained either directly from the sediment or scoured off gravel granules. Particles trapped by the dense setation of the 2nd and 3rd maxillipeds are brushed off and ingested.

The distribution of the various types of setae on the mouthparts is mapped and structure of the mouthparts and their setae is correlated with function. Sediment collected by the pereiopods is brushed off by the endopodites of the 3rd maxillipeds and transferred to the inner mouthparts by the endopodites of the 2nd maxillipeds. The basipodites of the 1st maxillae form a filter screen through which particles of suitable size are pushed by the 2nd maxillae. Rejected particles are discarded by the exhalant stream via the currents generated by the exopodites of the maxillipeds. Specialized setae on the 2nd maxillae scour detritus from the surface of gravel granules applied to these appendages by the 2nd and 3rd maxillipeds. Interlocking setae from different appendages form a number of screens the main function of which is to retain material in the buccal region. The exopodite and endopodite of the 1st maxilliped and the endopodites of the 1st and 2nd maxillipeds form a channel which funnels the exhalant respiratory current away from the crab. The main grooming appendages are the endopodites of the 3rd maxillipeds, however, most of the other mouthparts have a self-cleaning function.


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  1. Andrews PB (1973) Late quaternary continental shelf sediments off Otago Peninsula, New Zealand. NZJ Geol Geophys 16:793–830Google Scholar
  2. Boltt RE (1961) Antennary feeding in the hermit crab Diogenes brevirostris Stimpson. Nature, London 192:1099–1100Google Scholar
  3. Brock F (1926) Das Verhalten des Einsiedlerkrebses Pagurus arrosor Herbst wahrende des Suche und Aufnahme der Nährung. Z Morph Ökol Tiere 6:415–552Google Scholar
  4. Caine EA (1975) Feeding and masticatory structures of selected Anomura (Crustacea). J Exp Mar Biol Ecol 18:277–301Google Scholar
  5. Caine EA (1978) Habitat adaptations of Isocheles wurdemanni Stimpson (Crustacea: Anomura: Diogenidae) and seasonality of occurrences in Northwestern Florida. Texas Univ Austin Inst Mar Sci Contrib Mar Sci 21:117–123Google Scholar
  6. Caine EA (1980) Adaptations of a species of hermit crab (Decapoda, Paguridea) inhabiting sessile worm tubes. Crustaceana 38:306–310Google Scholar
  7. Factor JR (1978) Morphology of the mouthparts of larval lobsters, Homarus americanus (Decapoda, Nephropidae), with special emphasis on their setae. Biol Bull Mar Biol Lab Woods Hole 154:383–408Google Scholar
  8. Gerlach SA, Ekstrøm DK, Eckardt PB (1976) Filter feeding in the hermit crab, Pagurus bernhardus. Oecologia 24:257–264Google Scholar
  9. Greenwood JG (1972) The mouthparts and feeding behaviour of two species of hermit crabs. J Nat Hist 6:325–337Google Scholar
  10. Hyden FM, Forest J (1980) An in situ hermit crab from the early Miocene of Southern New Zealand. Palaeontology 23:471–474Google Scholar
  11. Jackson HG (1913) Eupagurus. LMBC Mem Typ Brit Plants Anim 21:1–79Google Scholar
  12. Kunze J, Anderson DT (1979) Functional morphology of the mouthparts and gastric mill in the hermit crabs Clibanarius taeniatus (Milne-Edwards), Clibanarius virescens (Krauss), Paguristes squamosus McCulloch and Dardanus setifer (Milne-Edwards) (Anomura:Paguridae). Aust J Mar Freshwater Res 30:683–722Google Scholar
  13. Markham JC (1977) Preliminary note on the ecology of Calcinus verrilli, an endemic Bermuda hermit crab occupying attached vermetid shells. J Zool London 181:131–136Google Scholar
  14. Miller DC (1961) The feeding mechanism of fiddler crabs with ecological considerations of feeding adaptations. Zoologica NY 46:89–100Google Scholar
  15. Orton JH (1927) On the mode of feeding of the hermit crab Eupagurus bernhardus and some other Decapoda. J Mar Biol Ass UK 14:909–921Google Scholar
  16. Patton WK, Robertson DR (1980) Pair formation in a coral inhabiting hermit crab. Oecologia 47:267–269Google Scholar
  17. Probert PK, Batham EJ, Wilson JB (1979) Epibenthic macrofauna off southeastern New Zealand and mid-shelf bryozoan dominance. NZJ Mar Freshwater Res 13:379–392Google Scholar
  18. Roberts MH (1968) Functional morphology of mouth parts of the hermit crabs, Pagurus longicarpus and Pagurus pollicaris. Chesapeake Sci 9:9–20Google Scholar
  19. Schuhmacher H (1977) A hermit crab, sessile on corals, exclusively feeds by feathered antennae. Oecologia 27:371–374Google Scholar
  20. Thomas WJ (1970) The setae of Austropotamobius pallipes (Crustacea: Astacidae). J Zool London 160:91–142Google Scholar
  21. Thompson MT (1904) The metamorphosis of the hermit crab. Proc Boston Soc Nat Hist 31:147–209Google Scholar

Copyright information

© Springer-Verlag 1982

Authors and Affiliations

  • Patrick J. Schembri
    • 1
  1. 1.Portobello Marine LaboratoryPortobelloNew Zealand

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