Collin Lab

Directory of Calyptraeid Researchers

Dr. Rachel Collin

Rachel Collin

Staff Scientist
Smithsonian Tropical Research Institute
Unit 9100, Box 0948
DPO, AA 34002

Web: Rachel Collin - Smithsonian
Voice: +0-507-212-8766

Research in my laboratory focuses on using calyptraeid gastropods to address questions in three main areas: Evolution of mode of development, systematics and taxonomy, and the evolutionary ecology of sex change. 
Evolution of mode of development:  I use a comparative phylogenetic approach to understand the evolution of mode of development (larval development vs. direct development) in marine invertebrates. My comparative data for calyptraeid gastropods show that evolutionary changes in development may be large and rapid. I am currently interested in examining the form and function of different developmental stages of calyptraeids to understand what features are lost in direct developers.  Work is underway to compare the ability to capture and digest particles across species with each different kind of development.

Systematics and taxonomy:  To provide a phylogenetic context for my comparative data on development, I have worked for several years on the molecular and morphological systematics of calyptraeid gastropods (Crepidula, Calyptraea, and Crucibulum).  The taxonomy of calyptraeids is still uncertain in many cases. For example, in the last few years I have described several new species from collections near marine laboratories, and numerous other species still await description. Systematic analyses of 90 calyptraeid species has shown that taxonomic divisions based on shell characters are often misleading and that the group displays pervasive parallelisms and convergences in morphology, development, and general lifestyle.

Evolutionary Ecology of Sex Change:  Life history theory predicts that animals should change sex at a size or age that maximizes their lifetime reproductive output.  Calyptraeid gastropods are protandrous (males change to females) sex changers. Some species are solitary while others form pairs or large stacks of individuals. Preliminary data on a few species suggests that animals change sex in response to their associations with conspecifics. I am currently conducting laboratory experiments to determine if species with different social structures in the field respond differently to associations with conspecifics and how differences in environmental conditions factor into this.


  1. Collin, R. 1995. Sex, size, and position: A test of models predicting the size at sex change in the protandrous gastropod Crepidula fornicata. American Naturalist. 146(6): 815-831.
  2. Collin, R. 2000. Phylogeny of the Crepidula plana (Gastropoda: Calyptraeidea) cryptic species complex in North America. Canadian Journal of Zoology. 78: 1500-1514.
  3. Collin, R. 2000. Sex change, reproduction and development of Crepidula adunca and C. lingulata (Gastropoda: Calyptraeidae) The Veliger. 43: 24-33.
  4. Collin, R. 2001. The effects of mode of development on phylogeography and population structure of North Atlantic Crepidula (Gastropoda: Calyptraeidae). Molecular Ecology. 10: 2249-2262.
  5. Chaparro, O., J. L. Carpentier, and R. Collin. 2002. Embryonic velar structure and function in sibling species of Crepidula with different modes of development. Biological Bulletin. 203: 80-86.
  6. Collin, R. 2002. Another last word on Crepidula convexa and a description of C. ustulatulina sp. nov. (Gastropoda: Calyptraeidae) from the Gulf of Mexico. Bulletin of Marine Science. 70(1): 177-184.
  7. Collin, R. and Cipriani, R. 2003. Dollo’s Law and the re-evolution of shell coiling. Proceedings of the Royal Society, Series B. 270: 2551-2555.
  8. Collin, R. 2003. Phylogenetic relationships among calyptraeid gastropods and their implications for the biogeography of speciation. Systematic Biology. 52(5): 618-640.
  9. Collin, R. 2003. The utility of morphological characters in gastropod phylogenetics: An example from the Calyptraeidae. Biological Journal of the Linnean Society. 78: 541-593.
  10. Collin, R. 2003. World-wide patterns of development in calyptraeid gastropods. Marine Ecology Progress Series. 247: 103-122.
  11. Collin, R. 2004. The loss of complex characters, phylogenetic effects, and the evolution of development in a family of marine gastropods. Evolution. 58 (7): 1488-1502.
  12. Collin, R. 2005. Crepidula badisparsa sp. nov. (Gastropoda: Calyptraeidae) from Bocas del Toro Province, Panama. Caribbean Journal of Science. 41(2): 269-276.
  13. *Collin, R., M. McLellan, K. Gruber, and C. Bailey-Jourdain. 2005. Effects of conspecific associations on size at sex change in three species of calyptraeid gastropods. Marine Ecology Progress Series 293:89-97
  14. Collin, R. 2005. Development, phylogeny, and taxonomy of Bostrycapulus (Caenogastropoda: Calyptraeidae), an ancient cryptic radiation. Zoological Journal of the Linnean Society 144: 75-101.
  15. Chaparro, O.R., C.L. Saldivia, S.V. Pereda, C.J. Segura, Y.A. Montiel, and R. Collin. 2005. The reproductive cycle and development of Crepipatella fecunda (Gastropoda: Calyptraeidae) from Southern Chile. Journal of the Marine Biological Association of the UK. 85: 157-161.
  16. Collin, R., M. Wonham, and K. R. Barr. 2006. Crepidula convexa Say 1822 (Caenogastropoda: Calyptraeidae) in Washington State, USA. American Malacological Bulletin. 21: 113-116
  17. Collin, R. 2006. Sex ratio, life history invariants, and patterns of sex change in a family of protandrous gastropods. Evolution 60: 735-745.
  18. Collin, R. Chaparro, O. R., Winkler, F. and D. Veliz. 2007. Molecular phylogenetic and embryological evidence that feeding larvae have been reacquired in a marine gastropod. Biological Bulletin 212: 83-92.
  19. Collin, R and E. Rolan. 2008. Bostrycapulus heteropoma n. sp. and Bostrycapulus tegulicius (Gastropoda: Calyptraeidae) from western Africa. The Veliger. 51:8-14.
  20. Collin, R., P. Farrell and S. Cragg. 2009. Confirmation of the identification and establishment of the South American slipper limpet Crepipatella dilatata (Lamark 1822) (Caenogastropoda: Calyptraeidae) in Northern Spain. Aquatic Invasions 4: 377-380.
  21. Collin, R. and M. Z. Salazar. 2010. Temperature-mediated plasticity and genetic differentiation in egg size and hatching size among populations of Crepidula (Calyptraeidae: Gastropoda). Biological Journal of the Linnean Society. 99(3): 489-499
  22. Collin, R., A. A. Ramos-Esplá, and A. Izquierdo. 2010. Identification of the South Atlantic spiny slipper limpet Bostrycapulus odites Collin 2005 (Caenogastropoda: Calyptraeidae) on the Spanish Mediterranean coast. Aquatic Invasions. 5: 197-200
  23. Henry, J. J., R. Collin and K. J. Perry. 2010. The slipper snail, Crepidula: An emerging lophotrochozoan model system. Biological Bulletin. 218: 211-229
  24. Collin, R. 2010. Maternal effects but not brood order or female size contribute to intraspecific variation in egg size of two marine gastropods. Marine Ecology Progress Series.

Go to Directory