INTERTIDAL THALASSINIDEAN SHRIMPS (THALASSINIDEA, AND ) OF THE WEST COAST OF BAJA CALIFORNIA, MEXICO: ANNOTATED CHECKLIST, KEY FOR IDENTIFICATION, AND SYMBIONTS

BY

ERNESTO CAMPOS1,3),ALMAR.DECAMPOS1) and IVÁN MANRIQUEZ1,2) 1) Laboratorio de Sistemática de Invertebrados, Facultad de Ciencias, Universidad Autónoma de Baja California, Apartado Postal 296, Ensenada, Baja California 22800, Mexico 2) Pro-Esteros, Calle 4a # 210, Zona Centro, Ensenada, Baja California 22800, Mexico

ABSTRACT

An annotated checklist of the intertidal species of Thalassinidea of the west coast of Baja California, Mexico, and an updated comparative list of their commensals and parasites that live inside the burrows of these or on their body, is provided. Four species of burrower shrimps, the mud shrimp, Upogebia macginiteorum (Williams, 1986) [Upogebiidae] and the ghost shrimps, Neotrypaea biffari (Holthuis, 1991), N. californiensis (Dana, 1854), and N. gigas (Dana, 1852) [Callianassidae] were collected during our survey. For each species, the diagnostic features, distribution, and some ecological remarks are recorded, which include: (1) a revised diagnoses for the Neotrypaea species; (2) a range extension for N. californiensis and N. gigas from San Quintin Bay, Baja California, Mexico to El Coyote Estuary, near Point Abreojos, Baja California Sur, México; (3) nine new records of symbiotic associations; and (4) the first record for Mexico of the commensal , Clausidium vancouverense (Haddon, 1912). An illustrated key to the identification of the intertidal species of thalassinideans of the Californian Province is included as well.

RESUMEN

El presente estudio proporciona una lista faunística comentada de las especies de Talasínidos intermareales de la costa oeste de Baja California, México, y una lista comparativa actualizada de los comensales y parásitos que viven dentro de la madriguera de estos crustáceos o sobre su cuerpo. Cuatro especies de camarones amadrigadores fueron recolectados durante nuestro estudio, el camarón de fango Upogebia macginiteorum (Williams, 1986) [familia Upogebiidae] y los camarones fantasma Neotrypaea biffari (Holthuis, 1991), N. californiensis (Dana, 1854) y N. gigas (Dana, 1852) [familia Callianassidae]. Para cada especie, las características diagnosticas, la distribución y algunas observaciones ecológicas son registradas, lo cual incluye: (1) una diagnosis revisada para las especies de Neotrypaea; (2) la extensión del ámbito geográfico para N. californiensis y N. gigas

3) Corresponding author; e-mails: [email protected] or: [email protected] © Koninklijke Brill NV, Leiden, 2009 Crustaceana 82 (10): 1249-1263 Also available online: www.brill.nl/cr DOI:10.1163/001121609X12481627024454 1250 E. CAMPOS, A. R. DE CAMPOS & I. MANRIQUEZ de la Bahía de San Quintín, Baja California, México hasta el estero El Coyote, cerca de Punta Abreojos, Baja California Sur, México; (3) el registro de nueve nuevas asociaciones simbióticas y (4) el primer registro para México del copépodo comensal Clausidium vancouverense (Haddon, 1912). Se incluye también una clave de identificación de las especies de talasínidos intermareales de la provincia Californiana.

INTRODUCTION Thalassinidean shrimps of the families Callianassidae and Upogebiidae are infaunal, soft-bodied, lobster-like decapod crustaceans that burrow into sand, gravel, sand flats, and mud flat areas in quiet bays and estuaries (see Felder, 2001). They have the abdomen longer than the cephalothorax and possess a posterior, fan- like structure formed by the combination of uropods and telson. All are burrowers, with a pair of subchelate or chelate chelipeds and a row of setae along the posterior margin of pereopod 2 (Poore, 1994). In general, these species play a very important role in the ecology of soft-bottom systems by resuspending organic matter and inorganic particles, a mechanism known as bioturbation, which may significantly influence the abundance and distribution of the infaunal and epifaunal community (Peterson, 1977; Brenchley, 1981; Posey, 1986a, b, 1987; Posey et al., 1991). In spite of the high abundance of these species in the soft-bottoms of estuaries of the Baja California Peninsula, little is known about species richness, distribution patterns, life history, and ecology. Further, commensals and parasites, that live inside their burrow or on their body, have received little attention, too. During an ecological survey in soft-bottom habitats of bays and estuaries along the west coast of Baja California, Mexico, four intertidal species of thalassinidean shrimps were collected, three Callianassidae and one Upogebiidae. An annotated checklist of these species is presented herein, which includes a range extension of the permanent populations of Neotrypaea californiensis (Dana, 1854) and N. gigas (Dana, 1854) from San Quintin Bay, Baja California to El Coyote estuary, i.e., near Point Abreojos, Baja California Sur, Mexico. In addition, an updated list of all parasites and commensals associated with these four species, and with Upogebia lepta Williams, 1986 and U. pugettensis (Dana, 1852), two species of mud shrimps that inhabit the Californian Province but that were not collected during this study, is also included. Specimens collected have been deposited in the Laboratorio de Sistemática de Invertebrados of the Facultad de Ciencias, Universidad Autónoma de Baja California.

MATERIAL AND METHODS Four estuaries of the west coast of Baja California, Mexico were visited: (1) Punta Banda, Todos los Santos Bay, Ensenada, Baja California, Mexico (31◦40-