Title

Island Endemism, Morphological Stasis, and Possible Cryptic Speciation in Two Coral Reef, Commensal Leucothoid Amphipod Species Throughout Florida and the Caribbean

Authors

Vincent P. Richards, Cornell University
Michael J. Stanhope, Cornell University
Mahmood S. Shivji, Nova Southeastern UniversityFollow

Document Type

Article

Publication Date

2-2012

Publication Title

Biodiversity & Conservation

Keywords

Coral reefs, Biological diversity, Ecosystem biology

ISSN

0960-3115

Volume

21

Issue/No.

2

First Page

343

Last Page

361

Abstract

Coral reefs are believed to be one of the most diverse ecosystems, but the true magnitude of their biodiversity and patterns of endemism is uncertain. This uncertainty stems partly from the relative paucity of investigations on the small, difficult to collect taxa (cryptofauna) that may make up the majority of reef biodiversity and require specialized expertise for morphological identification. To assess the extent of diversity in some of the reef micro-cryptofauna, we analyzed 414 bp of the mitochondrial cytochrome oxidase subunit I gene from 556 individuals representing two brooding amphipod species (Leucothoe ashleyae and Leucothoe kensleyi). These amphipods are commensal inside the branching vase sponge Callyspongia vaginalis, and were sampled throughout Florida and the Caribbean. Phylogenetic analyses revealed 11 deeply divergent, strongly supported lineages (seven L. ashleyae and four L. kensleyi) each with very narrow geographic ranges. The level of intraspecific lineage divergence for both morphospecies was among the highest reported for any marine crustacean (12.4–26.0% uncorrected), and exceeded that of congeners from nine diverse amphipod families, as well as the patristic genetic distance suggested as a threshold for crustacean species delineation. These findings suggest a history of cryptic speciation within each morphospecies, concomitant with a pronounced period of morphological stasis involving each of the morphotypes. The observation of multiple, highly divergent, evolutionary significant units, each endemic to Florida and Caribbean island locations, supports the emerging view that coral reef biodiversity, especially in the cryptofaunal component, is likely vastly underestimated.

Comments

©Springer Science+Business Media B.V. 2011

NSUWorks Citation

Richards, Vincent P.; Michael J. Stanhope; and Mahmood S. Shivji. 2012. "Island Endemism, Morphological Stasis, and Possible Cryptic Speciation in Two Coral Reef, Commensal Leucothoid Amphipod Species Throughout Florida and the Caribbean." Biodiversity & Conservation 21, (2): 343-361. doi:10.1007/s10531-011-0186-x.

ResearcherID

G-4080-2013

DOI

10.1007/s10531-011-0186-x