taxonID	type	description	language	source
03E987B3FFF8FFE8FF458B863823BDD9.taxon	materials_examined	Material examined and new hosts. 1 female (hard stage), El Coyote Estuary, Punta Abreojos, Baja California Sur, Mexico, 26 ° 48 ' 43.62 " N, 113 ° 27 ' 54.98 " W, 16 July 1999, free-living; 1 adult female, intertidal, Los Bungalos, Tortugas Bay, Baja California Sur, Mexico, 27 ° 41 ' 55.52 " N, 114 ° 52 ' 45.45 " W, 8 - 9 April 2000, in Modiolus capax. Revised distribution. Akutan Pass, Alaska, U. S. A. to El Coyote Estuary, Punta Abreojos, Baja California Sur, Mexico (Campos 1996).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF8FFE8FF458B863823BDD9.taxon	biology_ecology	Hosts. Common hosts include the following bivalves: Modiolus capax, M. modiolus (Linnaeus, 1758), Mya arenaria Linnaeus, 1758, Mytilus californianus Conrad, 1837, and M. edulis Linnaeus, 1758. Occasional hosts include: Cyclocardia ventricosa (Gould, 1850), Leukoma staminea (Conrad, 1837), Saxidomus gigantea (Deshayes, 1839), Tivela stultorum, Tresus capax (Gould, 1850), and T. nuttallii (Conrad, 1837) (Pearce 1966; Garth & Abbott 1980; Campos 1996). Other hosts. Garth & Abbott (1980) recorded the Atlantic bivalve Cyclocardia borealis (Conrad, 1832) as an occasional host; however, the presence of this bivalve in the eastern Pacific should be confirmed. The record of Mytilus edulis also needs confirmation because this species is validly reported only from embayments in California U. S. A. Mytilids from open coastal area may belong to M. galloprovincialis Lamarck, 1819, or M. trossulus Gould, 1850 (D. B. Cadien, pers. comm.).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF8FFE8FF458B863823BDD9.taxon	discussion	Remarks. Species of Fabia can be separated from other genera of Pinnotheridae by the possession in adult females of two deep sulci on the carapace that extend from the orbit to the gastric region (Fig. 1 A) and males having a smooth, shiny, porcelain-like carapace and two or more fused abdominal somites (Campos 1996). Four species have so far been recorded from the eastern Pacific: Fabia carvachoi Campos, 1996, F. concharum (Rathbun, 1893), F. malaguena (Garth, 1948), and F. subquadrata. Both F. subquadrata and F. concharum overlap in their distribution and may inhabit the same host in Southern California, U. S. A and on the west coast of Baja California, Mexico. Females of both species can be separated using the morphology of the chela and third maxilliped. Fabia concharum has one row of setae on the ventral margin of the cheliped propodus (Fig. 2 A) and the length of the dactyl of the third maxilliped is less than one-half the length of propodus (Fig. 1 D). Fabia subquadrata, instead, has two rows of setae, one marginal and other submarginal, on the ventral region of the hand of cheliped (Fig. 2 B), and the length of the dactyl of the third maxilliped is more than one-half the length of propodus (Fig. 1 B, C). Males can also be separated by differences in the abdomen. Somites 2 – 4 are fused in F. subquadrata, the lateral margin of somite 5 - 6 with pubescence, and the telson is subcircular (Fig. 1 F). In contrast, F. concharum has fused abdominal somites 3 – 5 (Rathbun, 1918; but this needs confirmation), the lateral margin of the sixth somite is hairless, and the telson is subtrapezoidal (Fig. 1 E). Campos (1996) and Campos & Manning (1998) pointed out how these species can be separated from the Pacific Ocean congeners F. carvachoi of the Gulf of California, Mexico and F. malaguena of Malaga Bay, Colombia. The present record extends the southern distribution limit of F. subquadrata approximately 600 km from Ejido Eréndira, Baja California to El Coyote Estuary, Abreojos Point, Baja California Sur, Mexico and adds Modiolus capax as a new host for the adult female. Other pinnotherids commonly found in the mantle cavity of M. capax include Opisthopus transversus and F. concharum. This last species only has been recorded subtidally in Todos Santos Bay, Baja California and Tortugas Bay, Baja California Sur, both localities located on the west coast of Baja California (Campos et al. 1992; pers. obs.). Fabia subquadrata commonly is found in the mantle cavity of the mussel Mytilus californianus in California, U. S. A. and Baja California; nevertheless, M. modiolus is the common host in Puget Sound, Washington, U. S. A (Pearce 1966).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF8FFE7FF458C353950BF13.taxon	materials_examined	Material examined and new hosts. 1 female, Nov. 2014, from commercial catches, Ensenada shellfish market, collected in Punta Colonet, Ensenada, Baja California, Mexico (30 ° 57 ' 43.65 " N, 116 ° 19 ' 22.44 " W) in Tivela stultorum.	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF8FFE7FF458C353950BF13.taxon	distribution	Distribution. Santa Cruz, California, U. S. A to Laguna de San Ignacio, Baja California Sur, Mexico (Campos & Manning 2000).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF8FFE7FF458C353950BF13.taxon	biology_ecology	Hosts. Symbiont in the giant Pacific chiton Cryptochiton stelleri (von Middendorff, 1847); the gastropods Aplysia vaccaria Winkler, 1955, Bulla gouldiana Pilsbry, 1895, Conus californicus Reeve, 1844, Lithopoma undosum (Wood, 1828) [= Megastraea undosa (W. Wood)], Megathura crenulata (Sowerby I, 1825), Navanax inermis (J. G. Cooper, 1862), and Neverita lewisii (Gould, 1847); the bivalves Atrina tuberculosa (G. B. Sowerby I, 1835), Crassadoma gigantea (J. E. Gray, 1825), Crassostrea gigas (Thunberg, 1793), Megapitaria squalida (G. B. Sowerby I, 1835), Modiolus capax, Modiolus sp., Mytilus edulis (see below), Nuttallia nuttallii, Pholas sp., Platyodon sp., Pseudochama exogyra (Conrad, 1837), Tivela stultorum, Tresus nuttallii, Zirfaea sp., and Zirfaea pilsbryi Lowe, 1931. Also commensal in the tube of the polychaete Chaetopterus variopedatus (Renier, 1804), and the cloaca of the holothuroids Apostichopus californicus (Stimpson, 1857), A. parvimensis (Clark, 1913), and Molpadia arenicola (Stimpson, 1857), (Schmitt et al. 1975; Garth & Abbott 1980; Ricketts et al. 1980; Campos et al. 1992). Other hosts. Garth & Abbott (1980) recorded the species in the Atlantic bivalve Dinocardium robustum (Lightfoot, 1786), but the presence of this bivalve in the eastern Pacific should be confirmed. Likewise, the record of Mytilus edulis needs confirmation since this species is validly reported only from embayments in California U. S. A. Mytilids from open coastal area may belong to M. galloprovincialis or M. trossulus.	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF8FFE7FF458C353950BF13.taxon	discussion	Remarks. According to Hopkins & Scanland (1964) the occurrence of O. transversus in multiple host species is evidence of the non-specificity of this pinnotherid. Although this conclusion is evident, another interpretation is that the species needs more than one host to complete its life history. The generalist behavior along the life history of O. transversus probably involves a complex relationship with their invertebrate hosts. Host selection is most probably not by chance. Thus, following Hopkins & Scanland (1964) it is possible to hypothesize that young individuals of Opisthopus infest a temporary host like the giant Pacific chiton Cryptochiton, moving initially to one or several larger hosts, e. g. Lithopoma, Megathura, or Stichopus, followed by a final selection of a definitive host, e. g. Crassadoma, Molpadia, or Zirfaea in which crab grow until they reach the adult phase, including ovigerous females. I concur with Hopkins & Scanland (1964) that host selection may be linked to host size, which provides space for growth and shelter; however, different hosts may also provide different types of nutrients necessary for development and reproduction. Because O. transversus was recorded in the Gulf of California (Glassell 1935 a), for the past 20 years I have examined potential hosts in beaches around San Felipe, Puertecitos, and Bahía de Los Angeles, Gulf of California, Mexico, including species of Mytilidae, Veneridae, Solecurtidae, Cardidae, and Hiatellidae, but no pinnotherid assignable to this species have been collected. The juvenile males recorded by Glassell, which were unavailable for study, may belong to Pinnaxodes gigas Green, 1992, a species that morphologically resemble O. transversus and inhabits the Gulf of California (see below).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF7FFE2FF458FEF3FE8B8A7.taxon	materials_examined	Material examined. 1 male, Bajo Macho, northeast of Consag Rock, upper Gulf of California, Mexico, 31 ° 7 ' 26.38 " N, 114 ° 31 ' 50.68 " W, May 1995, shrimp trawl; 1 female, Kino Bay, Sonora Mexico, 28 ° 48 ' 33.66 " N, 111 ° 54 ' 59.26 " W in Pinna rugosa; 10 females, west coast of Baja California, near San Quintín, 30 ° 28 ' 31.58 " N, 116 ° 4 ' 30.27 " W, 19 Dec. 2011, in Panopea sp. (presumably P. generosa, see below).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF7FFE2FF458FEF3FE8B8A7.taxon	distribution	Distribution. Gulf of California: Bajo Macho, northeast of Consag Rock, upper Gulf of California; Tastiota estuary, Sonora, Mexico. West coast of Baja California, commercial catches near San Quintín, Baja California, Mexico (Green 1992; Campos et al. 1998; Emparanza et al. 2011; this work).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF7FFE2FF458FEF3FE8B8A7.taxon	biology_ecology	Hosts. Gulf of California: the bivalves Panopea globosa (Dall, 1898), Pinna rugosa (Sowerby, 1835) (new host) and west coast of Baja California Panopea sp., presumably P. ge n e ros a (new host), (Emparanza et al. 2011; this work).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF7FFE2FF458FEF3FE8B8A7.taxon	discussion	Remarks. The geoduck crab Pinnaxodes gigas is the largest pinnotherid crab ever recorded for the Americas, with fully developed female having a carapace width of up to 36 mm. Examination of recently dead specimens permitted corroborating the color pattern reported by Green (1992) and Campos et al. (1998): red orange spots (hexadecimal color # d 13 c 00) on the dorsal surface of carapace and ambulatory legs, whereas the ventral surface has shades of dark grayish orange (hexadecimal color # a 89 d 94) (Fig. 3 A). Other species including P. floridensis, from the Northwestern Atlantic, and Opisthopus transversus, from the Eastern Pacific, feature such red-spots as well, which Hopkins & Scanland (1964) explained as crabs eating carotenoid-food rich from their host. These species share a suborbicular to subpentagonal carapace, a third maxilliped with a spoon-shaped dactylus proximally inserted on the spatulate propodus, and males with a narrow and triangular abdomen (Figs. 3 B – D, F – H). There are nevertheless morphological differences between these species of Pinnaxodes and O. transversus, including the shape of the front, and the meri of ambulatory legs and telson (Campos et al. 1998). Pinnaxodes gigas and P. floridensis have entire the front, meri of ambulatory legs distally swollen, and telson of the males basally expanded (Fig. 3 B – E). Opisthopus transversus, in contrast, has an emarginate front, meri of ambulatory legs uniformly wide, and telson of the males not basally expanded (Fig. 3 F – I). Despite females of P. gigas being undescribed, the male diagnostic features of the front and ambulatory legs can be used to separate females of P. gigas from females of O. transversus (pers. obs.). The present record of P. gigas in Pinna rugosa is unusual. Several decapod symbionts are known from P. rugosa, including the pontoniine shrimps Pontonia pinnae Lockington, 1878, and P. simplex Holthuis, 1951 (Wicksten 1983, 1989; Campos et al. 1995; Paredes-Rios & Balart 1999). The published host data suggests that the preferred host for P. gigas in the Gulf of California is Panopea globosa, (Emparanza et al. 2011; pers. obs.). The strong and firm carapace, chelipeds, and ambulatory legs of this crab are shared with pinnotherids that evolved to live in symbiosis with sea cucumbers, e. g Pinnixa banharti Rathbun, 1918 (host Molpadia arenicola) or Holothuriophilus trapeziformis (Burger, 1895) (host Holothuria inornata Semper, 1868) (Hopkins & Scanland 1964; Campos 2007; Campos et al. 2012). Campos et al. (1998) suggested a sea cucumber as a potential host for P. gigas. The robust morphology of this crab allows to hypothesize that a host change probably occurred in P. gigas, first evolving as a symbiont in the cloaca of a sea cucumber, switching later to a geoduck clam, a burying bivalve that is characterized by large and fused siphons that resemble the body-shape of a sea-cucumber. The strong and firm body of P. gigas does not match the soft carapace and weak pereiopods of pinnotherids that evolved as symbionts of bivalves, e. g. species in Pinnotherinae sensu stricto (Campos 2009). It therefore possible that geoducks clams, Panopea spp., have been more recently exploited as hosts of P. g i ga s. According to Emparanza et al. (2011) P. globosa from Playa del Sol (open coast), Empalme, Sonora, Mexico were infested with at least one crab each, infestation rate being 100 %, but some clams were infested by heterosexual pairs or even three individuals per host recording an average of 1.4 crabs by host. Conversely, a population of P. globosa from Altata lagoon system, Sinaloa, Mexico was uninfested by P. gi gas (Góngora-Gómez et al. 2016; pers. comm). Cáceres-Martínez & Vásquez-Yeomans (2008) recorded an unidentified pinnotherid crab in P. ge n e ros a, presumably P. gigas. Because the known distribution of geoducks in Baja California is putatively disjunt, specimens of P. gi g as from San Quintín herein recorded were probably from P. generosa (see Calderon- Aguilera et al. 2010). The shells of the clam hosts were unfortunately destroyed and their identities were not confirmed. Confirmation of this host is desirable, since several species of subtropical and tropical species of crabs have been recently discovered in San Quintín Bay (Campos & Campos 2012). It is possible that the sub-tropical Panopea globosa may occur within the southern limit of P. ge n e ro s a, between San Quintín and Canoas Point (29 ° 25 ’ N, 115 ° 06 ’ W; González-Peláez et al. 2013) on the west coast of Baja California. Most of the publications dealing with the distribution of Panopea along the west coast of Baja California cut the northern distribution of P. globosa at Magdalena Bay, with only one extralimital record by González-Peláez et al. (2013), and the southern distribution of P. g e ne ro s a in San Quintín-El Tomatal (28 ° 29 ' 9.75 " N, 114 ° 4 ' 1.60 " W) (Aragón-Noriega et al. 2012; González-Peláez et al. 2013; pers. obser.). Both species may nevertheless overlap their distribution between Magdalena Bay and El Tomatal on the west coast of the Baja California, a transitional biogeographic region for marine biota of the Californian, Mexican, and Cortez provinces (Brusca & Wallerstein 1979) that is periodically affected by El Niño and La Niña oscillations (Wang & Fielder 2006). This may influence the distribution of species of the region including species of Panopea and their symbionts (see Campos & Campos 2012).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF2FFE3FF458F9B38EAB8CB.taxon	diagnosis	Diagnosis. Carapace slightly broader than long, subquadrate to orbicular in outline, convex, curving downwards towards margins, surface smooth, naked, regions not defined. Front deflexed, rounded, not protruding, central portion continued downward as triangular process between antennules, smaller triangular processes at sides partly separating orbits from antennular fossettes. Orbits ovate, wide inner hiatus partly filled by base of antennas; eye peduncles very short, stout, cornea minute. Antennules oblique; antennular fossettes communicate each other beneath front. Third maxillipeds oblique, nearly fitting buccal area; merus broad, smooth, subquadrate, outer margin produced into broadly rounded laminate expansion; propodus oblong, distally rounded; dactylus spatulate, articulated near base, extending somewhat beyond propodus. Chelipeds moderate, smooth, naked; hands narrow, rather thick, widest immediately behind articulation of dactyl; fingers nearly or quite as long as palm, subconical, not conspicuously dentate on inner margins, partly covered by very short, dense pubescence. Pereiopods 2 - 4 subequal, pereiopod 5 smaller, all smooth, little compressed, dactyli acute, nearly straight, those pereiopod 5 longer, more slender than preceding pairs. Abdomen of female nearly circular in outline, covers entire sternal surface; six somites and telson separated, fourth, fifth and sixth being subequal, larger than others (modified from Holmes, 1895).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF2FFE3FF458F9B38EAB8CB.taxon	distribution	Distribution. Santa Cruz (type locality), Monterey, California, U. S. A. (Holmes 1895, 1900).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF2FFE3FF458F9B38EAB8CB.taxon	biology_ecology	Hosts. Unknown.	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF2FFE3FF458F9B38EAB8CB.taxon	discussion	Remarks. Pinnotheres nudus is known by its original description based on two syntype females collected at Santa Cruz, California, U. S. A. The two syntypes deposited in the California Academy of Sciences were destroyed in the San Francisco fire after the earthquake of April 18, 1906. Measurements of the syntypes given by Holmes (1895) (cl 20 mm, cw 24 mm; cl 15.5 mm, cw 19 mm). For more than a century there have been no new published records for this species. Campos & Manning (2000) nevertheless suggested that P. nudus should be placed in synonymy with Opisthopus transversus. Both species share several features including a large antenna, visible dorsally (Fig 4 A, E), a third maxilliped with a carpus that is shorter than the spatulate propodus, and a spoonshaped dactylus that is inserted proximally on the ventral margin of the propodus, with its apex extending beyond the tip of this article (Fig. 4 D, H). Both species possess pereiopods 2 – 4 that are subequal in length and shape, whereas the pereiopods 5 are the shortest. Furthermore, the abdomen (Fig 4 B, E) is nearly circular, composed of six somites and a freely articulating telson, with somites 4 – 6 subequal and larger than the others. Although these shared features may suggest that both species are synonymous, a reappraisal of their morphology showed some important features that were overlooked by Campos & Manning (2000). Pinnotheres nudus has a front that is deflexed, rounded, not protruding (Fig. 4 E), the central portion continued downward as a triangular process between the antennules; the subconical fingers of the chela are not conspicuously dentate along the inner margins, and although described as long as the palm, the original figure shows that both pollex and dactylus are longer than the palm (Fig. 4 G), and the dactyli of pereiopods 2 – 4 are acute, nearly straight whereas those of pereiopods 5 are relatively longer and more slender than in the preceding pairs. In contrast, O. transversus has a slightly produced, deflexed, almost straight, emarginate front (Fig. 4 A); the fingers of the chela are shorter than the palm and the cutting edge of the fingers has one small tooth at the base of dactylus and two or three at base of the pollex (Fig. 4 C), and the dactyli of pereiopods 2 – 4 are uniformly curved and small, whereas the dactyli of the pereiopods 5 are no longer than those of pereiopods 2 – 4 and all are of similar shape. These features allow to clearly distinguish both species so P. nudus should be removed from the synonymy of O. transverus and considered a valid species. The morphology of the third maxilliped described above and the shape and relative length of the dactyli of pereiopods 2 – 5 support the exclusion of P. nudus from Pinnotheres Bosc, 1802. The species is nevertheless retained temporally in Pinnotheres awaiting the collection of additional material.	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF3FFE0FF458F073AB5BCC7.taxon	materials_examined	Material examined. Gulf of California: 2 females (1 juvenile, 1 gravid), Playa Kino Viejo, Sonora, 28 ° 75 ' N, 112 ° 00 ' W, 24 Jan 1985, in Argopecten irradians concentricus (Say, 1822); 2 females (1 ovigerous), 24 Jan 1985, in A. i. concentricus; 1 ovigerous, 2 May 1983, in Pinctada mazatlanica (Hanley, 1855); 1 female, 18 May 1984, in P. mazatlanica; 3 females (2 ovigerous), 4 Nov. 1984, in P. mazatlanica, Punta San Pedro, Bahía Concepción, Baja California Sur, 26 ° 49 ' 46.95 " N, 111 ° 52 ' 19.21 " W. West coast of Baja California: 4 males and 30 females, 4 April 1987, Estero El Cardón, Laguna de San Ignacio, Baja California Sur, 26 ° 47 ' 40.38 " N, 113 ° 9 ' 4.49 " W, in Argopecten ventricosus (G. B. Sowerby II, 1842); 4 males (2 juveniles), 2 females (1 ovigerous) Banco El Zacatoso, Laguna Ojo de Liebre, Guerrero Negro, Baja California Sur, Mexico, 27 ° 53´05 ” N; 114 ° 08´39 ” W, 9 Jan 2013 in Nodipecten subnodosus (G. B. Sowerby I, 1835) (new host); 2 females juveniles, Banco La Concha, Laguna Ojo de Liebre, Guerrero Negro, Baja California Sur, Mexico, 27 ° 49´21 ” N; 114 ° 14´25 ” W, 9 Jan 2013 in N. subnudosus. Additional material examined. 1 ovigerous female (Museum of Zoology, University of Costa Rica, MZ – UCR 2220 – 11), northeast side Cabo Blanco Is., dredged parallel to the line coast, 30 – 40 m depth, 16 – 17 May 1998, Costa Rica, 9 ° 33´26.67 ” N, 85 ° 07´05.61 ” W. Revised distribution. Playa Kino Viejo, Sonora, (Gulf of California) and west coast of Baja California Sur to Scammon’s Lagoon, Guerrero Negro, Baja California Sur, Mexico to Panama Bay, Panama (Schmitt et al. 1973; Campos 1989; present record).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF3FFE0FF458F073AB5BCC7.taxon	biology_ecology	Hosts. Mollusca: Bivalvia: Pectinidae; A. i. concentricus, A. ventricosus, N. subnudosus (new host); and Pteridae, P. mazatlanica (Campos-González 1988; Campos 1989; present study).	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF3FFE0FF458F073AB5BCC7.taxon	distribution	Distribution and host removed. Records of T. margarita from El Rosario, west coast of Baja California in Crassadoma giganteus (Gray, 1825) and the San Felipe area, northern Gulf of California, in Limaria pacifica (d'Orbigny, 1846) and Barbatia reeveana (d'Orbigny, 1846) by Campos (1989 b) are confirmed misidentifications. Their taxonomic status is to be discussed in a forthcoming publication.	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
03E987B3FFF3FFE0FF458F073AB5BCC7.taxon	discussion	Remarks. The American genus Tumidotheres consist of three species: the Atlantic T. maculatus (Say) and the Pacific T. margarita and T. orcutti (Rathbun, 1918). All these species share a swollen carapace covered with short, dense, and deciduous tomentum, a third maxilliped with a narrowly spatulate dactylus, inserted in angular notch in middle of ventral margin of propodus; the dactyl of the last ambulatory leg being much longer than that of the other ambulatory legs in adult females, and the abdomen with six somites and a freely articulating telson. Tumidotheres margarita, which seems to prefer scallops (family Pectinidae), can be separated from its only known Pacific Ocean congener, T. orcutti (host unknown), by the unique dentition of the cutting edge of the cheliped pollex, which is armed with small teeth, all similar in size (Fig. 5 C – D). In contrast, the pollex of T. orcutti has a blunt proximal lobe and a row of small teeth, the two distal teeth being conspicuously the largest (Fig. 5 A – B). Some aspects of the life history of T. margarita were revised by Campos (1989 b), who pointed out this species develops into a hard stage crab (Christensen & McDermott 1958) after several molts of the infestive and prehard stages. Presumably, hard stage males and females leave their host to form a copulatory swarming in open sea, reinfesting their host after mating. Data from Felix-Pico (1992) suggest that T. margarita, found in A. circularis, start copulation during late winter and spring. After copulatory swarming, females re-infest their host, reaching the ovigerous stage during late spring and summer, and disappearing during autumn-winter. The discovery of males of T. margarita, in prehard and hard stage, and females in posthard stages (Felix-Pico 1992) suggest this crab completes its postplanktonic life history in a single host species, which is re-infested after copulation in open water. Similarly T. maculatus re-infests to Mytilus edulis after copulation in open water (Pearce 1969). The absence of females in prehard and hard stage of T. margarita is remarkable, which may suggest that these female stages may live in a different host that was overlooked or that the males in prehard and hard stage recorded by Felix-Pico (1992) included undetected females. Males and females in pre-hard and hard stages are identical and have a narrow abdomen, which results in them frequently being identified as males. The sexes in Pinnotheridae at prehard and hard stage can be only recognized by locating the gonopods in males (see Campos 1989 b, 2013) and pleopods in females along with the presence of female gonopores on the sixth thoracic sternite and male gonopods on the eighth thoracic sternite.	en	Campos, Ernesto (2016): The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae). Zootaxa 4170 (2): 311-329, DOI: 10.11646/zootaxa.4170.2.5
