Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

A Comparative Study of Some Mouthpart Adaptations of Uca annulipes (H. Milne Edwards, 1837) and U. vocans (Linnaeus, 1758) (Brachyura, Ocypodidae) in Relation to Their Habitats

Shirley S. L. Lim
Crustaceana
Vol. 77, No. 10 (Nov., 2004), pp. 1245-1251
Published by: Brill
Stable URL: http://www.jstor.org/stable/20107433
Page Count: 7
  • Read Online (Free)
  • Download ($34.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
A Comparative Study of Some Mouthpart Adaptations of Uca annulipes (H. Milne Edwards, 1837) and U. vocans (Linnaeus, 1758) (Brachyura, Ocypodidae) in Relation to Their Habitats
Preview not available

Abstract

The density of spoon-tipped setae (ST setae) along the inner edge of the merus of the left second maxilliped of two Singapore species of fiddler crabs, Uca annulipes and U. vocans, was studied. A larger proportion of the inner merus edge was covered with ST setae in U. annulipes as compared to U. vocans (two-thirds vs. half of the edge, respectively). The number of ST setae did not differ significantly between males and females in both species (ANCOVA, slopes and intercepts, p > 0.05) suggesting there is no sexual dimorphism in mouthpart adaptations for these species. The combined regression equation (male + female data; CW = carapace width) for U. annulipes (n = 91) was #ST setae = 15.6 + 14.7CW with r² = 0.63, that for U. vocans (n = 100) being #ST setae = 32.4 + 9.91CW with r² = 0.66. For any given size of crab, significantly more ST setae were present in Uca annulipes (a sandy habitat crab) than in U. vocans (a muddy habitat species). These results provide quantitative evidence that fiddler crabs that inhabit sandy habitats possess more ST setae (an adaptation for processing sandy sediments), than those occurring in muddy habitats. /// La densité des soies à extrémité en cuiller (soies ST) sur le bord interne du mérus du deuxième maxillipède gauche a été étudiée chez deux espèces de crabes violonistes de Singapour, Uca annulipes et U. vocans. Une plus grande partie du bord interne du mérus était recouverte de soies ST chez U. annulipes, par rapport à U. vocans (les deux tiers pour la moitié du bord, respectivement). Le nombre de soies ST ne différait pas significativement entre mâles et femelles chez les deux espèces (ANCOVA, pente et intersections, p > 0.05), ce qui suggère qu'il n'y a pas de dimorphisme sexuel dans les adaptations des appendices buccaux chez ces deux espèces. L'équation de régression combinée (données mâle + femelle; CW = largeur de la carapace) (n = 91) était pour U. annulipes, # soie ST = 15,6 + 14,7CW avec r² = 0,63, pour U. vocans (n = 100), # soie ST = 32,4 + 9,91CW avec r² = 0, 66. Pour une taille donnée de crabe, il y avait significativement plus de soies ST chez Uca annulipes (crabe de sables) que chez U. vocans (crabe de milieu vaseux). Ces résultats semblent mettre en évidence que les crabes violonistes vivant en milieu sableux possèdent plus de soies ST (adaptation à la vie dans les sédiments sableux) que ceux qui vivent en milieu vaseux.

Page Thumbnails

  • Thumbnail: Page 
[1245]
    [1245]
  • Thumbnail: Page 
1246
    1246
  • Thumbnail: Page 
1247
    1247
  • Thumbnail: Page 
1248
    1248
  • Thumbnail: Page 
1249
    1249
  • Thumbnail: Page 
1250
    1250
  • Thumbnail: Page 
1251
    1251