A new species and two new genera of pinnotherid crabs from the northeastern Pacific Ocean, with a reappraisal of the subfamily Pinnotherinae de Haan, 1833 (Crustacea: Brachyura: Pinnotheridae)

Abstract

Two monotypic genera, Enigmatheres new genus, and Bonita new genus, are described to receive Fabia canfieldi Rathbun, 1918, and Bonita mexicana new species respectively. Enigmatheres can be distinguished from other Pinnotheridae by the third maxilliped having a gently curved outer margin, with a carpus that is larger than the conical propodus and a dactylus that is inserted on the middle third of the ventral margin of the propodus, walking legs 2 that are asymmetrical in length and the dactyli of walking legs 1, 3 and 4 that are short, slender, conical, slightly curved up to hooked and hard tip. Bonita can be distinguished from other Pinnotheridae by the presence of two sulci on the carapace, protruding anterolateral margins of the carapace, walking leg 3 asymmetrical in length and larger than other walking legs, and walking leg 4 with a clavate propodus. These two new genera and 25 additional ones (nine with hesitation), including Pinnotheres Bosc, 1802 (type genus of Pinnotherinae de Haan, 1833), share a carapace that is soft and thin, walking legs 1-4 that are slender and feeble, antennae with a protuberance on the basal segment and the known zoea larvae being very similar, particularly with an abdomen that widens from somite 1 to 5 and a telson that is laterally convex and posteriorly trilobed. These adult and larval shared features support the monophyly of these genera and clearly diagnose the subfamily Pinnotherinae de Haan, 1833 sensu stricto.

Phylogeny of Calyptraeotheres Campos, 1990 (Crustacea, Decapoda, Brachyura, Pinnotheridae) with the description of C. pepeluisi new species from the tropical Mexican Pacific

“…The larval morphology and molecular results suggest a closely relationship between Calyptraeotheres, Clypeasterophilus, Dissodactylus, and Tumidotheres but, these results mutually do not confirm the relationship of these genera with Tunicotheres and Pinnaxodes. Our results on larval morphology support a more closely relationship between the monotypic Tunicotheres and Pinnotheres taylori and in a less degree with members of the subfamily Pinnotherinae sensu Campos (2009) (see Fig. 1-2).…”

“…Palacios-Theil et al (2009) subsequently performed a molecular analysis of selected members of the family Pinnotheridae to ascertain their phylogenetic relationships. Their results suggested a close phylogenetic relationship between Calyptraeotheres and Tumidotheres which, collectively with the genera Dissodactylus, Clypeasterophilus and Tunicotheres, formed the so-called clade-IIC of the Pinnotherinae sensu Palacios-Theil et al (2009, Fig.1; but see discussion on this subfamily in Campos 2009). Our new analysis, on the updated matrix of Marquez & Pohle (1995), permitted to recognize that members of the genera Calyptraeotheres, Clypeasterophilus, Dissodactylus, Pinnaxodes Heller, 1865 and Tumidotheres (see Table 1, Pinnotherid V) share the larval characters analyzed and in general possess a very similar morphology.…”

“…Remarkably, Tunicotheres moseri and P. taylori share a similar kind of host (tunicates) (Rathbun 1918;Campos 1996) and both have abbreviated larval development (see Hart 1935;Bolaños et al 2004) which is highly derived. The systematics and classification of Pinnotheres taylori as well as of other crabs symbiotic of tunicates is currently under study by the first author, however, all the gathered morphological and ecological evidence suggest it, like Tunicotheres, neither belong in Pinnotheres nor in the subfamily Pinnotherinae sensu Campos (2009). The zoeae of this subfamily show a generalized and unique laterally convex telson with the furcal shafts greatly reduced to the size of the median projection and adults have a well developed protuberance on the basal antennal article (Campos 2009).…”

Phylogeny, phylogeography, and systematics of the American pea crab genusCalyptraeotheres Campos, 1990, inferred from molecular markers

“…Understanding the systematics of this family has been the aim of many studies, which have generally been based on comparative morphology (e.g. Griffith, ; Manning & Felder, ; Marques & Pohle, ; Ahyong & Ng, ; Campos, ; Campos & Hernández‐Ávila, ) and more recently have included molecular data (Harrison, ; Harrison & Hanley, ; Palacios‐Theil et al ., ).…”

Calyptraeotheres sp. nov. (Crustacea: Decapoda: Pinnotheridae), symbiont of the slipper shell Crepidula striolata Menke, 1851 (Mollusca: Gastropoda: Calyptraeidae) from the Gulf of California, Mexico

“…Brachyuran crabs of the family Pinnotheridae in the Mexican Pacific are relatively well known, in great part due to the extensive study of this group of crabs by Ernesto Campos (see Campos 2006Campos , 2009. The family is represented in the Mexican Pacific by 47 species (Hendrickx 1995;unpublished).…”