Synalpheus regalis

Synalpheus regalis Duffy, 1996

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Overview

Overview

Synalpheus regalis is a unique species of sponge-dwelling snapping shrimp, and the first described example of eusociality in the sea (Duffy 1996a).  Like social insects such as ants and honeybees, Synalpheus regalis lives in large colonies consisting of one breeding female "queen" and typically 100 or more non-breeding workers that jointly defend the sponge against intruders (Duffy 1996b, 2007).  Allozyme work has confirmed that most colonies consist of full-sibs produced by the queen and possibly a single male "king."

S. regalis belong to the gambarelloides species group in the genus Synalpheus, and molecular work suggests that eusociality evolved independently at least three times in this group.

Author(s): Hultgren, Kristin
Rights holder(s): Hultgren, Kristin

Ecology and Behavior

Natural History

Synalpheus regalis lives in coral reefs, most commonly in the sponge species Xestospongia spp. and Hyattella intestinalis.

Author(s): Hultgren, Kristin
Rights holder(s): Hultgren, Kristin

Habitat and Host Associations

Lives in coral reefs; associate of sponges (phylum Porifera), specifically the sponges Xestospongia spp. and Hyattella intestinalis.

Author(s): Hultgren, Kristin
Rights holder(s): Hultgren, Kristin

Reproduction and Life History

Like several other species in the genus Synalpheus, S. regalis exhibits eusocial population structure (defined here as living in large colonies with a single breeding female).  This species undergoes direct development, with embryos hatching into crawling larvae.

Author(s): Hultgren, Kristin
Rights holder(s): Hultgren, Kristin

Distribution

Western Atlantic: Belize (Duffy 1996a,c, Macdonald et al. 2006; RĂ­os and Duffy 2007); Jamaica (Macdonald et al. 2009)

 

Author(s): Hultgren, Kristin
Rights holder(s): Hultgren, Kristin

Evolution and Phylogenetics

Evolution

Synalpheus regalis is one of at least six described eusocial Synalpheus species in the gambarelloides species complex, making this group a model system for examining the evolution of eusociality in the sea (Duffy et al. 2000, Morrison et al. 2004).

Author(s): Hultgren, Kristin
Rights holder(s): Hultgren, Kristin

Phylogenetics

Sequenced in Morrison et al. 2004 (as regaBE02, regaBE01); sequences available in GenBank for 16S mtDNA (AF230271 ) and COI mtDNA (AF230794).

Author(s): Hultgren, Kristin
Rights holder(s): Hultgren, Kristin

Identification and Taxonomy

Systematics and Identification

Synalpheus regalis belongs to the gambarelloides species complex (Duffy, 1996) within the genus Synalpheus.  The species name is derived from the Latin "regalis," meaning royal, referring to the social structure of this species in which large colonies are headed by a single "queen".

Author(s): Hultgren, Kristin
Rights holder(s): Hultgren, Kristin

Morphology

Like most members of the Synalpheus gambarelloides species group, Synalpheus regalis has a streamlined body adapted to living in sponge canals and a thick brush of setae on the minor chela (claw).  Maximum body size (carapace length, or CL) of males is 3.2 mm; females, 4.14 mm (Macdonald et al. 2009). Color: Body translucent to faint translucent-orange; distal tips of major chela brighter orange, ovaries and embryos pale green (Duffy 1996b, Rios and Duffy 2007).

Author(s): Hultgren, Kristin
Rights holder(s): Hultgren, Kristin

Synonomies

Synalpheus "rathbunae C" (Duffy 1996c, BJLS); Zuzalpheus regalis (Rios and Duffy 2007).

Author(s): Hultgren, Kristin
Rights holder(s): Hultgren, Kristin

Specimen information

Type locality: Carrie Bow Cay, Belize (Duffy, 1996), types stored at the National Museum of Natural History, Smithsonian Institution (USNM).  Holotype: USNM 280092, allotype: none.

Author(s): Hultgren, Kristin
Rights holder(s): Hultgren, Kristin

References

Duffy, J. E. (1996).  Eusociality in a coral-reef shrimp. Nature (London). 381, 512-514. Abstract
Duffy, J. E. (1996).  Species boundaries, specialization, and the radiation of sponge-dwelling alpheid shrimp. Biological Journal of the Linnean Society. 58, 307-324. Abstract
Duffy, J. E. (1996).  Synalpheus regalis, new species, a sponge-dwelling shrimp from the Belize Barrier Reef, with comments on host specificity in Synalpheus. Journal of Crustacean Biology. 16, 564-573. Abstract
Duffy, J. E. (1998).  On the frequency of eusociality in snapping shrimps (Decapoda: Alpheidae), with description of a second eusocial species. Bulletin of Marine Science. 63, 387-400. Abstract
Duffy, J. E., & Macdonald K. S. (2010).  Kin structure, ecology and the evolution of social organization in shrimp: a comparative analysis. Proceedings of the Royal Society Series B. 277, 575-584.
Duffy, J. E., Morrison C. L., & Rios R. (2000).  Multiple origins of eusociality among sponge-dwelling shrimps (Synalpheus). Evolution. 54, 503-516. Abstract
Macdonald, K. S., Hultgren K. M., & Duffy J. E. (2009).  The sponge-dwelling snapping shrimps (Crustacea, Decapoda, Alpheidae, Synalpheus) of Discovery Bay, Jamaica, with descriptions of four new species. Zootaxa. 2199, 1-57.
Macdonald, K. S., Rios R., & Duffy J. E. (2006).  Biodiversity, host specificity, and dominance by eusocial species among sponge-dwelling alpheid shrimp on the Belize Barrier Reef. Diversity And Distributions. 12, 165-178. Abstract
Morrison, C. L., Rios R., & Duffy J. E. (2004).  Phylogenetic evidence for an ancient rapid radiation of Caribbean sponge-dwelling snapping shrimps (Synalpheus). Molecular Phylogenetics & Evolution. 30, 563-581. Abstract
Toth, E., & Bauer R. T. (2007).  Gonopore sexing technique allows determination of sex ratios and helper composition in eusocial shrimps. Marine Biology. 151, 1875-1886. Abstract
Toth, E., & Duffy J. E. (2005).  Coordinated group response to nest intruders in social shrimp. Biology Letters. 1, 49-52. Abstract