Molecular Ecology Resources (2011) 11, 271–278 doi: 10.1111/j.1755-0998.2010.02946.x
DNA BARCODING Genetic barcoding of marine leeches (Ozobranchus spp.) from Florida sea turtles and their divergence in host specificity
AUDREY E. McGOWIN,* TRIET M. TRUONG,* ADRIAN M. CORBETT,† DEAN A. BAGLEY,‡§ LLEWELLYN M. EHRHART,‡§ MICHAEL J. BRESETTE,§ STEVEN T. WEEGE§ and DAVE CLARK§ *Department of Chemistry, Wright State University, Dayton, OH 45435, USA, †Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH 45435, USA, ‡Department of Biology, University of Central Florida, Orlando, FL 32816, USA, §Inwater Research Group, Inc., 4160 NE Hyline Dr., Jensen Beach, FL 34957, USA
Abstract Ozobranchus margoi and Ozobranchus branchiatus are the only two species of marine turtle leeches (Ozobranchus spp.) known to inhabit the Atlantic coast of the United States and theGulfofMexico.Inearlyreports of fibropapillomatosis (FP) in green turtles (Chelonia mydas), O. branchiatus was implicated as a vector in the transmission of Fibropapilloma- associated turtle herpesvirus (FPTHV). It is imperative that the leech species be identified to elucidate the role Ozobranchus spp. may play in disease transmission. In this study, Ozobranchus branchiatus has been identified for the first time on a log- gerhead (Caretta caretta) turtle, and the molecular data for this species is now available for the first time in GenBank. Both species of leeches were also found infecting a single C. mydas. Using morphological taxonomy combined with distance- and character-based genetic sequence analyses, this study has established a DNA barcode for both species of Ozobranchus spp. leech and has shown it can be applied successfully to the identification of leeches at earlier stages of development when morphological taxonomy cannot be employed. The results suggest a different haplotype may exist for O. branchiatus leeches found on C. caretta versus C. mydas. Leech cocoon residue collected from a C. mydas was identified using the new method.
Keywords: cocoon, DNA barcoding, Fibropapillomatosis-associated turtle herpesvirus, new host record, Ozobranchus branchiatus, Ozobranchus margoi, sea turtle leech, two species infection Received 1 September 2010; revision received 11 October 2010; accepted 21 October 2010
1975). A distinguishing morphological characteristic of Introduction the Ozobranchidae family is finger-like terminally There are only two known species of marine turtle branching lateral protuberances (gills or branchidae) that leeches (Ozobranchus spp.) known to inhabit the Atlantic decrease in complexity and size from the anterior to the coast of the United States and the Gulf of Mexico, Ozo- posterior and begin on segment XIII of the abdomen branchus margoi and Ozobranchus branchiatus. The primary (Sawyer 1986). The primary difference in these two spe- host for O. margoi is the loggerhead turtle (Caretta caretta) cies of leeches is in the number of gills with one pair per but O. margoi has been reported on green turtles (Chelonia segment; O. margoi has five pairs (Davies 1978) and mydas), hawksbill turtles (Eretmochelys imbricata) and O. branchiatus sports seven pairs (Raj & Penner 1962). Kemp’s Ridley turtles (Lepidochelys kempi) as well (Bunk- Both species have a short, segmented body with two eye ley-Williams et al. 2008). Only rarely is a host other than spots, a proboscis and a large posterior sucker. These C. mydas reported for O. branchiatus, although its occur- leeches attach to the mouth, neck, cloaca and under the rence on black turtles (Chelonia agassizi a.k.a. Chelonia flippers of turtles and deposit eggs in cocoons on the car- mydas of the Eastern Pacific) (McDonald & Dutton 1990), apace. Almost nothing is known about the life cycle of hawksbill turtles (Bunkley-Williams et al. 2008), and olive sea turtle leeches, including whether they can exist in the ridley turtles (Lepidochelys olivacea) in Mexico has been absence of a turtle host or if they have alternate hosts. documented (Hernandez-Vazquez & Valadez-Gonzalez Ozobranchus spp. can be very small (millimetres in 1998). These warm water marine leeches belong to the length) with various life stages so differentiation amongst family Rhynchobdellida, Ozobranchidae (Sawyer et al. species is difficult. Only a few descriptions of Ozobran- Correspondence: Audrey E. McGowin, Fax: +1 937 775 2717; chus spp. exist in the scientific literature (Sawyer et al. E-mail: [email protected] 1975) primarily because of the challenges of studying