@inbook {950,
	title = {Crustacea},
	booktitle = {Fauna Japonica sive Descriptio Animalium, quae in Itinere per Japoniam, Jussu et Auspiciis Superiorum, qui Summum in India Batava Imperium Tenent, Suscepto, Annis 1823{\textendash}1830 Collegit, Notis, Observationibus et Adumbrationibus Illustravit},
	year = {1844},
	pages = {1-243},
	publisher = {Lugduni-Batavorum},
	organization = {Lugduni-Batavorum},
	address = {Leiden},
	author = {de Haan, W.},
	editor = {von Siebold, P.F.}
}
@article {609,
	title = {New Caridea from the Dominican Republic},
	journal = {American Museum Novitates},
	volume = {1410},
	year = {1949},
	pages = {1-22},
	chapter = {1},
	author = {Armstrong, J.C.}
}
@article {282,
	title = {Synalpheus shrimps (Crustacea: Decapoda: Alpheidae). I. The Gambarelloides group, with a description of a new species},
	journal = {Memoires of the Hourglass Cruises},
	volume = {7},
	number = {2},
	year = {1984},
	pages = {1-125},
	author = {Dardeau, M.R.}
}
@article {344,
	title = {Multiple origins of eusociality among sponge-dwelling shrimps (Synalpheus)},
	journal = {Evolution},
	volume = {54},
	number = {2},
	year = {2000},
	note = {Article.0014-3820English},
	month = {April},
	pages = {503-516},
	abstract = {As the most extreme expression of apparent altruism in nature, eusociality has long posed a central paradox for behavioral and evolutionary ecology. Because eusociality has arisen rarely among animals, understanding the selective pressures important in early stages of its evolution remains elusive. Employing a historical approach to this problem, we used morphology and DNA sequences to reconstruct the phylogeny of 13 species of sponge-dwelling shrimps (Synalpheus) with colony organization ranging from asocial pair-bonding through eusociality. We then used phylogenetically independent contrasts to test whether sociality was associated with evidence of enhanced competitive ability, as suggested by hypotheses invoking an advantage of cooperation in crowded habitats. The molecular, morphological, and combined data each strongly supported three independent origins of monogynous, multigenerational (eusocial) colony organization within this genus. Phylogenetically independent contrasts confirmed that highly social taxa, with strong reproductive skew, have significantly higher relative abundance within the host sponge than do less social taxa, a result that was robust to uncertainty in tree topology and varying models of character change. A similar tendency for highly social species to share their sponge with fewer congener species was suggestive, but not significant. Because unoccupied habitat appears to be limiting for many sponge-dwelling shrimp species, these data are consistent with hypotheses that cooperative social groups enjoy a competitive advantage over less organized groups or individuals, where independent establishment is difficult, and that enemy pressure is of central importance in the evolution of animal sociality.},
	keywords = {[01500] Evolution, [07003] Behavioral biology - Animal behavior, [07502] Ecology: environmental biology - General and methods, [64054] Invertebrata:comparative, [75112] Malacostraca, altruism, Animalia, Arthropoda, Arthropods, asocial pair-bonding, Behavior, colony organization: monogynous, Crustacea, Crustaceans, dna, eusociality, Evolution and Adaptation, experimental morphology, Invertebrata, Invertebrates, Malacostraca: Animals, Morphology, multigenerational, multiple origins, phylogeny, physiology and pathology - Arthropoda: crustacea, social evolution, Synalpheus [Malacostraca]},
	url = {file://localhost/Users/kristinhultgren/Desktop/Papers/Duffy_Morrison_Rios_2000.pdf},
	author = {Duffy, J. E. and Morrison, C. L. and Rios, Ruben}
}
@article {406,
	title = {Colony structure of the social snapping shrimp Synalpheus filidigitus in Belize},
	journal = {Journal Of Crustacean Biology},
	volume = {19},
	number = {2},
	year = {1999},
	note = {Article.0278-0372English},
	month = {May},
	pages = {283-292},
	abstract = {Several species of sponge-dwelling alpheid shrimps (Synalpheus) exhibit unusual colony organizations reminiscent of those found in social insects, but few of these shrimp species have been studied in detail. We sampled colonies of S. filidigitus from its two main hosts, the sponges Oceanapia sp. and Xestospongia spp., at Carrie Bow Cay, Belize. Colonies contained all size classes of shrimp, from recent hatchlings to mature, brooding females. The majority of colonies consisted of <30 individuals, although a few reached much greater numbers (maximum = 94 in Oceanapia and 121 in Xestospongia). In all but one of the colonies sampled containing mature female(s), only a single female (the "queen") was present. Distinct cohorts of juveniles, apparently produced by the resident female, were recognizable in several colonies, and the total number of individuals in the colony was strongly correlated with the resident female s size and fecundity. These observations suggest that, as previously shown for the eusocial S. regalis, the colony is a close-kin group consisting mainly of the queen s philopatric offspring. Comparison of females from a range in colony sizes revealed an apparent ontogenetic transformation in the queen s morphology. Although smaller (presumably younger) females were morphologically similar to males, queens from larger colonies were considerably larger than males, had proportionally longer and wider abdomens, and had the massive major chela of the first pereiopod replaced with a small chela identical to the normal minor first chela. Colonies of S. filidigitus are similar in organization to those of S. regalis, suggesting that S. filidigitus may be eusocial according to the traditional definition. This brings to 3 the number of species of Synalpheus reported to exhibit this paradoxical social organization.},
	keywords = {[00532] General biology - Miscellaneous, [07003] Behavioral biology - Animal behavior, [07502] Ecology: environmental biology - General and methods, [11102] Anatomy and Histology - Gross anatomy, [16501] Reproductive system - General and methods, [39000] Porifera, [64054] Invertebrata:comparative, [75112] Malacostraca, Animalia, Arthropoda, Arthropods, Behavior, body size, colony structure, Crustacea, Crustaceans, Ecology: Environmental Sciences, eusociality, experimental morphology, fecundity, female, Invertebrata, Invertebrates, juvenile, Malacostraca: Animals, male [Malacostraca], Oceanapia sp.: sponge [Porifera], physiology and pathology - Arthropoda: crustacea, Porifera: Animals, social organization, Synalpheus filidigitus: snapping shrimp, Xestospongia spp.: sponge [Porifera]},
	author = {Duffy, J. E. and Macdonald, Kenneth S.}
}
@article {329,
	title = {Phylogenetic evidence for an ancient rapid radiation of Caribbean sponge-dwelling snapping shrimps (Synalpheus)},
	journal = {Molecular Phylogenetics \& Evolution},
	volume = {30},
	number = {3},
	year = {2004},
	note = {Article.1055-7903 (ISSN print)English},
	month = {March},
	pages = {563-581},
	abstract = {A common challenge in reconstructing phylogenies involves a high frequency of short internal branches, which makes basal relationships difficult to resolve. Often it is not clear whether this pattern results from insufficient or inappropriate data, versus from a rapid evolutionary radiation. The snapping shrimp genus Synalpheus, which contains in excess of 100 species and is a prominent component of coral-reef faunas worldwide, provides an example. Its taxonomy has long been problematic due to the subtlety of diagnostic characters and apparently widespread variability within species. Here we use partial mt COI and 16S rRNA sequences and morphological characters to reconstruct relationships among 31 species in the morphologically well-defined gambarelloides species group, a putative clade of obligate sponge associates that is mostly endemic to the Caribbean and contains the only known eusocial marine animals. Analysis of the combined data produced a single tree with good support for many terminal clades and for relationships with outgroups, but poor support for branches near the base of the gambarelloides group. Most basal branches are extremely short and terminal branches are long, suggesting a relatively ancient, but rapid radiation of the gambarelloides group. This hypothesis is supported by significant departure from a null model of temporally random cladogenesis. Calibration of divergence times among gambarelloides-group species using data from three geminate pairs of Synalpheus species separated by the isthmus of Panama suggests a major radiation between apprx5 and 7 Mya, a few My before final closure of the Panamanian seaway during a period of spreading carbonate environments in the Caribbean; a second, smaller radiation occurred apprx4 Mya. This molecular evidence for a rapid radiation among Caribbean marine organisms in the late Miocene/early Pliocene is strikingly similar to patterns documented from fossil data for several other Caribbean reef-associated invertebrate taxa. The similar patterns and timing of cladogenesis evidenced by molecular and fossil data for different Caribbean and East Pacific taxa suggests that the radiation involved a wide range of organisms, and strengthens the case that poor basal resolution in the gambarelloides group of Synalpheus reflects a real evolutionary phenomenon. The rapid radiation also helps explain the historical difficulty of diagnosing species in Synalpheus.},
	keywords = {16S rRNA sequences, adaptive radiation},
	author = {Morrison, C. L. and Rios, R. and Duffy, J. E.}
}
@article {369,
	title = {Gonopore sexing technique allows determination of sex ratios and helper composition in eusocial shrimps},
	journal = {Marine Biology},
	volume = {151},
	number = {5},
	year = {2007},
	note = {0025-3162},
	month = {Jun},
	pages = {1875-1886},
	abstract = {An evaluation of the social organization and sexual system of eusocial species of Synalpheus has been hindered because it has not been possible to determine the sexual composition of colony helpers (workers). The external sexual characters typically used to sex caridean shrimps are lacking in Synalpheus. We used SEM sexing technique to determine the sexual composition of helpers in colonies of Synalpheus regalis, S. rathbunae, S. chacei, S. rathbunae A (see Morrison et al. Mol Phylogen Evol 30:563-568, 2004), and S. filidigitus. Colonies consisted of both sexes and sex ratios of helpers generally conformed to 50:50 female to male. Females were characterized by gonopores with U-shaped slits on the coxae of the third pereopods (first walking legs) while males had oval gonopore openings on the coxae of the fifth pereopods (third or last walking legs). In S. chacei, S. filidigitus, and S. rathbunae A, a few helpers were found that had both male and female gonopores (intersexes). All three reproductive females (queens) of S. filidigitus examined were intersexes. Sexing of helpers allowed us to test some hypotheses about sexual differences in helper morphology that might indicate task specialization (division of labor). Male helpers were not different from female ones in body size (except in S. regalis: males somewhat larger) and in fighting chela size. The lack of sexual dimorphism in these characters suggests no male-female specialization in colony tasks such as defense. The presence of male and female helpers similar in size suggests that the sexual system of these eusocial species is gonochoristic, although protandry of some sort in S. filidigitus can not be ruled out. The intersexuality observed in a few individuals may be due to developmental anomalies, protandry, or even simultaneous hermaphroditism. Finally, the sexing technique allowed us to establish that new colonizers of unoccupied sponges in S. rathbunae are a single male and female of helper size.},
	url = {<Go to ISI>://000246614300025},
	author = {Toth, E. and Bauer, R. T.}
}
@article {412,
	title = {Biodiversity, host specificity, and dominance by eusocial species among sponge-dwelling alpheid shrimp on the Belize Barrier Reef},
	journal = {Diversity And Distributions},
	volume = {12},
	number = {2},
	year = {2006},
	month = {Mar},
	pages = {165-178},
	abstract = {Alpheid shrimp represent an abundant and diverse, but poorly characterized, component of the cryptic biodiversity of coral reefs worldwide. Sponge-inhabiting alpheids provide a promising model system for exploring patterns of cryptic reef biodiversity because their habitats (hosts) are discrete and qualitatively distinct units. We tabulated data from 14 years of collections at Carrie Bow Cay, Belize to quantify patterns of diversity, host specificity, and dominance among sponge-dwelling shrimp (Synalpheus), with special attention to eusocial species. From > 600 sampled sponges of 17 species, we recognized at least 36 Synalpheus shrimp species. Of these, 15 (42\%) were new to science. Species accumulation curves suggest that we have sampled most of the Synalpheus diversity at Carrie Bow Cay. Diversity of sponge-dwelling Synalpheus was slightly higher in shallow water, probably because of greater habitat diversity, than in deep water. Host specificity was surprisingly high, with > 50\% of all shrimp species found in only a single sponge species each, although some shrimp species used as many as six hosts. Cohabitation of individual sponges by multiple shrimp species was rarer than expected by chance, supporting previous distributional and behavioural evidence that competition for hosts is strong and moulds patterns of host association. The fauna of most well-sampled sponge species was dominated, both in numbers of individuals and in frequency of occurrence, by eusocial species. Eusocial shrimp species also inhabited a significantly greater number of sponge species than did non-social shrimp. Consequently, > 65\% of shrimp in our quantitative samples belonged to the four eusocial species, and on a per-species basis, eusocial species were 17 times as abundant as non-social species. Our data suggest that the highly diverse sponge-dwelling shrimp assemblage of the Belize Barrier Reef is structured by competition, and that eusociality has allowed a small number of species to dominate the sponge resource.},
	url = {file://localhost/Users/kristinhultgren/Desktop/Papers/Macdonald_Rios_\&Duffy_2006.pdf},
	author = {Macdonald, K. S. and Rios, R. and Duffy, J. E.}
}
@article {432,
	title = {Kin structure, ecology and the evolution of social organization in shrimp: a comparative analysis},
	journal = {Proceedings of the Royal Society Series B},
	volume = {277},
	year = {2010},
	pages = {575-584},
	chapter = {575},
	author = {Duffy, J. E. and Macdonald, K. S.}
}
