Ernesto Campos

TUMIDOTHERES, A NEW GENUS FOR PINNOTHERES MARGARITA SMITH, 1869, AND PINNOTHERES MACULATUS SAY, 1818 (BRACHYURA: PINNOTHERIDAE)

The genus Tumidotheres is erected to receive its type species Pinnotheres margarita Smith, 1869, from the East Pacific, and P. maculatus Say, 1818, from the West Atlantic. It differs from other pinnotherid genera principally in 3 features: (1) the gastric and cardiac regions are separated from the branchiohepatic area by depressions, all these regions tumid; (2) the palp of the third maxilliped is composed of 3 articles, with the carpus shorter than the spatulate propodus, the dactylus narrowly spatulate, inserted medially on the propodal inner margin and not overreaching the tip of this latter article; and (3) male and female abdomen composed of 7 free abdominal somites. An analysis of morphology of several postplanktonic stages of T. (formerly Pinnotheres) margarita suggested that this species should be considered as a senior synonym of P. pubescens (Holmes, 1894), which apparently was described from a hard-stage female. In addition, the life history, phylogenetic relationships, and larval morphology of Tumidotheres are discussed.

Clypeasterophilus, a new genus to receive the small-palped species of the Dissodactylus complex (Brachyura : Pinnotheridae)

ABSTRACT Clypeasterophilus, new genus, is erected to receive 4 species currently assigned to Dissodactylus Smith, 1870: D. rugatus Bouvier, 1917; D. juvenilis Bouvier, 1917; D. stebbingi Rathbun, 1918; and D. ususfructus Griffith, 1987. The new genus is characterized by (1) the continuous anterolateral margins of the carapace, (2) the palp of the third maxilliped slender and shorter than widest point of the ischium-merus, (3) the male telson subpentagonal, and (4) gonopods that narrow abruptly at their tips. Clypeasterophilus is an exclusive symbiont of irregular echinoids of the genus Clypeaster.

Distribution of the Red Swamp Crayfish Procambarus Clarkii (Girard, 1852) (Decapoda: Cambaridae) in Mexico: An Update

ABSTRACT A study of the distribution of Procambarus clarkii in northern Mexico led to the conclusion that this crayfish is native to Central Rio Bravo and its tributary, Rio Salado, in Chihuahua, Coahuila, Nuevo Leon, and Tamaulipas. The Sierra Madre Oriental and the Meseta del Norte, with elevations of 1,000 or more m above sea level, provide barriers that have inhibited more western natural dispersion. We point out that P. clarkii is exotic in central-west Tamaulipas, central Nuevo Leon, western Chihuahua, Sonora, and Baja California, where its presence has resulted from repeated man-made introductions. The habitat preferred by this crayfish in northern Mexico is lotic (73%), with a mud bottom (62.5%), and aquatic vegetation was present in 50% of the known localities.

Partial Revision of Pinnotherid Crab Genera with a Two-Segmented Palp on the Third Maxilliped (Decapoda: Brachyura)

Two new genera in the Pinnotheridae are recognized from the northwestern Atlantic, Gemmotheres, new genus (type species Pinnotheres chamae Roberts, 1975) and Tunicotheres, new genus (type species Pinnotheres moseri Rathbun, 1918). These genera shared a 2-segmented palp on the third maxilliped with Calyptraeotheres Campos, 1990, Dissodactylus Smith, 1870, Ostracotheres H. Milne Edwards, 1853, and Xanthasia White, 1846. They differ in shape, texture, and hardness of the carapace, shape and relative length of third maxilliped articles, relative length of the walking legs, and relative length and shape of their articles. Comparisons among these genera are provided in a dichotomous key based on adult female characters. During the last five years I have studied the systematics of a subgroup of pinnotherid crabs which are characterized by a twosegmented palp on the third maxilliped (lacking a dactylus). The first result of this study was the erection of the genus Calyptraeotheres Campos, 1990 (type species Fabia granti Glassell, 1933) from the Mexican Pacific. This work led to the systematic reassessment of the remaining American Pinnotheridae with a two-segmented palp on the third maxilliped, Pinnotheres moseri Rathbun, 1918, and P. chamae Roberts, 1975. The analysis of several morphological and ecological features has led to the conclusion that: (1) P. moseri and P. chamae do not belong in the genus Pinnotheres Bosc, 1802 [type species P. pisum (Linnaeus, 1767)] or any other named genera in the Pinnotheridae, and (2) several autapomorphies separate these taxa at the generic level.

Intertidal thalassinidean shrimps (Thalassinidea, Callianassidae and Upogebiidae) of the west coast of Baja California, Mexico: annotated checklist, key for identification, and symbionts

[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 crustaceans 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, Mexico; (3) nine new records of symbiotic associations; and (4) the first record for Mexico of the commensal copepod, Clausidium vancouverense (Haddon, 1912). An illustrated key to the identification of the intertidal species of thalassinideans of the Californian Province is included as well. El presente estudio proporciona una lista faunistica comentada de las especies de Talasinidos intermareales de la costa oeste de Baja California, Mexico, y una lista comparativa actualizada de los comensales y parasitos que viven dentro de la madriguera de estos crustaceos o sobre su cuerpo. Cuatro especies de camarones amadrigadores fueron recolectados durante nuestro estudio, el camaron 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 caracteristicas diagnosticas, la distribucion y algunas observaciones ecologicas son registradas, lo cual incluye: (1) una diagnosis revisada para las especies de Neotrypaea ; (2) la extension del ambito geografico para N. californiensis y N. gigas de la Bahia de San Quintin, Baja California, Mexico hasta el estero El Coyote, cerca de Punta Abreojos, Baja California Sur, Mexico; (3) el registro de nueve nuevas asociaciones simbioticas y (4) el primer registro para Mexico del copepodo comensal Clausidium vancouverense (Haddon, 1912). Se incluye tambien una clave de identificacion de las especies de talasinidos intermareales de la provincia Californiana. , 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 crustaceans 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, Mexico; (3) nine new records of symbiotic associations; and (4) the first record for Mexico of the commensal copepod, Clausidium vancouverense (Haddon, 1912). An illustrated key to the identification of the intertidal species of thalassinideans of the Californian Province is included as well. El presente estudio proporciona una lista faunistica comentada de las especies de Talasinidos intermareales de la costa oeste de Baja California, Mexico, y una lista comparativa actualizada de los comensales y parasitos que viven dentro de la madriguera de estos crustaceos o sobre su cuerpo. Cuatro especies de camarones amadrigadores fueron recolectados durante nuestro estudio, el camaron 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 caracteristicas diagnosticas, la distribucion y algunas observaciones ecologicas son registradas, lo cual incluye: (1) una diagnosis revisada para las especies de Neotrypaea ; (2) la extension del ambito geografico para N. californiensis y N. gigas de la Bahia de San Quintin, Baja California, Mexico hasta el estero El Coyote, cerca de Punta Abreojos, Baja California Sur, Mexico; (3) el registro de nueve nuevas asociaciones simbioticas y (4) el primer registro para Mexico del copepodo comensal Clausidium vancouverense (Haddon, 1912). Se incluye tambien una clave de identificacion de las especies de talasinidos intermareales de la provincia Californiana. ]

Diversity and ecological remarks of ectocommensals and ectoparasites (Annelida, Crustacea, Mollusca) of echinoids (Echinoidea: Mellitidae) in the Sea of Cortez, Mexico

The diversity of symbiotic invertebrates on intertidal and shallow water echinoids of the northwestern Gulf of California was studied. Five ectosymbionts were found: three pinnotherid crabs, Dissodactylus lockingtoni Glassell (1935), Dissodactylus nitidus Smith (1870), and Dissodactylus xanthusi Glassell (1936); one eulimid gastropod, Turveria encopendema Berry (1956); and one polychaete, Struwela sp. We discovered seasonal fluctuation in D. nitidus Smith (1870) and D. xanthusi Glassell (1936), which result in these species being undetectable during the winter season when the temperature in the head of the Gulf of California drops to 14–18°C; the rest of the species are permanent residents in this area. An updated list of all external macrosymbionts of echinoids of the Mexican Pacific is presented.

Calyptraeotheres hernandezi (Crustacea: Brachyura: Pinnotheridae), a new crab symbiont of the West Indian cup-and-saucer Crucibulum auricula (Gmelin) (Mollusca: Gastropoda: Calyptraeidae) off Cubagua Island, Venezuela

ABSTRACT Calyptraeotheres hernandezi is described from off Cubagua Island, Caribbean Sea, Venezuela. The new species resembles C. granti (Glassell, 1933) from the eastern Pacific, with both taxa possessing a third maxilliped with an endopod palp of only two segments, i.e., with the dactylus missing, and the exopod with a thin and unsegmented flagellum. The new Atlantic species differs in the female having eyes that are visible from dorsal view, the propodi of the walking legs having subparallel margins, and the ventral margin of the pollex bearing a small fringe of setae. In contrast, the Pacific limpet crab C. granti has the eyes hidden from the dorsal perspective, the margin of the propodus of the walking legs tapered distally, and the ventral margin of the pollex with a well-developed fringe of setae. The austral species C. garthi (Fenucci, 1975) and C. politus (Smith, 1870) can be separated from the former two species by their third maxilliped having a rounded and minute dactylus that is inserted subdistally on the ventral margin of propodus. The new species inhabits the West Indian gastropod Crucibulum auricula (Gmelin). RESUMEN Calyptraeotheres hernandezi se describe de las vecindades de la isla Cubagua, Mar Caribe, Venezuela. La nueva especie se asemeja a C. granti (Glassell, 1933) del Pacifico oriental, ambas especies poseyendo el palpo del endópodo del tercer maxilipedio con 2 segmentos, i.e., el dáctilo esta ausente, y el exópodo con un flagelo delgado y no segmentado. La nueva especie atlántica difiere porque los ojos de la hembra son dorsalmente visibles, los márgenes de los própodos de las patas caminadoras son subparalelos y el margen ventral del dedo fijo posee un pequeño fleco de setas. En contraste, el cangrejo de la lapa del Pacifico, C. granti, tiene los ojos dorsalmente ocultos, el margen de los própodos de las patas caminadoras se estrecha distalmente y el margen ventral del dedo fijo posee un fleco de setas bien desarrollado. Las especies australes C. garthi (Fenucci, 1975) y C. politus (Smith, 1870) pueden separarse de las anteriores debido a que su tercer maxilípedo presenta un dáctilo pequeño y redondo que se inserta subdistalmente sobre el margen ventral del própodo. La nueva especie habita en la lapa Crucibulum auricula (Gmelin).

Remarks on the sexual dimorphism and taxonomy of Fabia Dana, 1851 (Crustacea, Brachyura, Pinnotheridae)

A study of the holotype of Pinnotheres hemphilli Rathbun, 1918, revealed it is an early post-hard female, not a male, of Fabia Dana, 1851. The morphology of Pinnotheres emiliai Melo, 1971 (based on a male specimen) and Fabia insularis Melo, 1971 (based on a female specimen) confirm earlier hypothesis that they belong to a sexually dimorphic species that should be known as F. emiliai (Melo, 1971). The redescription of the holotype of Fabia felderi Gore, 1986, supports its generic assignment and its relationship with F. emiliai. The implication of sexual dimorphism and intersexes in the taxonomy of Fabia is discussed.

On the pea crabs found in the chiton Tonicia chilensis (Frembly, 1827) (Mollusca, Polyplacophora: Chitonidae) identified as “ Orthotheres sp.” by Melzer & Schwabe (2008), and its reassignment to Calyptraeotheres Campos, 1990 (Crustacea: Pinnotheridae)

Crabs of the family Pinnotheridae have been considered a phylogenetically heterogeneous group and taxonomically problematic (Palacios-Theil 2009, 2016; Tsang et al. 2018). The lack of knowledge of sexual dimorphism and morphological variation throughout the life history for many species have complicated its taxonomy and has resulted in errors in its classification (Campos 1989, 1993, 2016). Consequently, if the taxonomy of these symbiotic crabs had been based on juveniles and undeveloped character states, the problems get even more serious (Campos 1989, 1993). Melzer Schwabe (2008) studied three juvenile crabs living in the chiton Tonicia chilensis (Frembly, 1827) (Polyplacophora: Chitonidae) collected in Muelle Dichato, Chile, and they identified them as the putative invasive stage of a species of Orthotheres Sakai, 1969. The crabs are of the typical juvenile pinnotherid form with a masculine habitus, including a suborbicular carapace, large eyes and a slender pleon (= abdomen) with the telson well defined (Ocampo et al. 2017). Unpublished observations on juveniles and adults of several species of pinnotherid crabs by the author, for example, Juxtafabia muliniarum (Rathbun, 1918), Dissodactylus lockingtoni Glassell, 1935, D. xantusi Glassell, 1936, Calyptraeotheres granti (Glassell, 1933), Austinotheres angelicus (Lockington, 1877) and Tumidotheres margarita (Smith, 1870) have revealed that the third maxilliped exhibit little morphological variation through the post-larval stages of development (from juvenile to adult). This appendage, including the partial or total fusion of the ischium and merus (Fig. 1A-G; Fig 2A, C-G), has been considered a valuable feature for distinguishing genera in the family Pinnotheridae (Bürger 1895; Rathbun 1918; Manning 1993; Ahyong Ng 2007; Campos 2009). According to Melzer Schwabe (2008) the ischium and merus of the third maxilliped are completely fused, the carpus is larger than the propodus and the small dactylus is subterminally inserted on the propodus (Fig 1C), and as such the juveniles studied are possibly members of the genus Orthotheres Sakai, 1969. A detailed re-examination of the third maxilliped, chela of pereiopod 1 (cheliped) and pleon, however, has shown otherwise. Campos (1989) discussed the taxonomy of Orthotheres and treated all the species he recognised as belonging to this genus; characterising its members by its diagnostic third maxilliped palp structure. Ng Ho (2014) rediagnosed the genus based on the type species, O. turboe Sakai, 1969, from Japan, and restricted it for three Indo-West Pacific species; commenting that the American species as well as some Indo-West Pacific taxa will need to referred to other genera when a full revision is done. This revision is now in progress by the author, PKL Ng and ST Ahyong. Until the revision is complete, the genus is treated here in the broader sense of Campos (1989) and Geiger Martin (1999).

A new pea crab species of the genus Arcotheres Manning, 1993 (Crustacea: Decapoda: Brachyura: Pinnotheridae) from India

A new species of pinnotherid crab, Arcotheres shahi n. sp., is described on the basis of specimens collected during a crustacean survey along the coastal areas of Pamban fishing harbor in the Gulf of Mannar, Tamil Nadu state, east coast of India. The new species resembles A. pernicola (Bürger, 1895), A. winckworthi (Gordon, 1936) and A. rayi Ahyong Ng, 2007, in having the dactyli of the longer fourth pereopod longer than that of fifth pereopod. Arcotheres shahi n. sp. differs from these three known species in the shape of female carapace, frontal region and chela, setal pattern on the dactyli of the fourth and fifth pereopods and relative length of the ambulatory pereiopods.