Molecular phylogeography of Tumidotheres maculatus (Say, 1818) and Zaops ostreus (Say, 1817) (Crustacea: Decapoda: Pinnotheridae) in the western Atlantic, with description of a new species and synonymy of Epulotheres Manning, 1993

ABSTRACT

The commensal crab genus Tumidotheres is reportedly represented along the western Atlantic coast by Tumidotheres maculatus, with populations distributed from temperate to tropical waters in North and South America. Western Atlantic populations of the related genus Zaops have been alternatively separated into the northern species Zaops ostreus and southern Zaops geddesi. We hypothesized that populations of T. maculatus comprised more than one species, much as currently accepted in Zaops. Molecular markers (COI, 16S-NADH1 complex, 12S, and histone 3) were used to infer relationships between sampled populations of Tumidotheres and Zaops. We found that most populations of Tumidotheres belonged to a single species, but that specimens from the western Caribbean Sea represented an undescribed congener, herewith described and named. Remarkably, all sequenced populations of Zaops were inseparable, leading us to question the validity of Z. geddesi as the southern counterpart of Z. ostreus. Though sequence analyses failed, we provisionally reassign Epulotheres angelae to the genus Zaops on the basis of morphological characters. Since Epulotheres is a monotypic genus, this synonymizes the genus with Zaops.

KEYWORDS:

• Antitropical distribution
• cryptic species
• evolution
• symbiosis

Acknowledgements

For access to field sites and study materials, we especially thank H. Bracken-Grissom, E. Campos, R. Collin, J. Cuesta, S. De Grave, J. Felder, G. Hernández, S. Jones, W. Lee, R. Lemaitre, R. Manning, F. Mantelatto, J. McDermott, V. Paul, M. Rice, R. Robles, C. Schubart, B. Thoma, J. Thoma, and E. Wenner. Essential laboratory assistance was provided by E. Garcia, R. Robles and B. Thoma. We express our gratitude to R. Bauer, J. Cuesta, S. France, and J. Neigel for their constructive reviews during the manuscript preparation as well as to H. Bracken-Grissom and P. K. L. Ng for their useful suggestions. Major support was provided under U.S. National Science Foundation grants NSF/BS&I DEB-0315995 and NSF/AToL EF-0531603, along with U.S. Food and Drug Administration contract number FDA-SOL-1087949. Varied programmes of the Smithsonian Institution provided support for partial coverage of work in Florida, Belize, and Panama. This is contribution number 195 of the UL-Lafayette Laboratory for Crustacean Research, number 1113 for the Smithsonian Marine Station, Ft. Pierce, and number 1017 for the Smithsonian CCRE programme.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by National Science Foundation [grant number NSF/AToL EF-0531603, NSF/BS&I DEB-0315995]; Smithsonian Institution; U.S. Food and Drug Administration [grant number FDA-SOL-1087949].