Catapaguroides A. Milne-Edwards & Bouvier, 1892

Komai, Tomoyuki & Rahayu, Dwi Listyo, 2013, The Hermit Crab Genus Catapaguroides A. Milne-Edwards & Bouvier, 1892 (Crustacea: Decapoda: Anomura: Paguridae) From The Bohol Sea, Philippines, With Descriptions Of Eight New Species, Raffles Bulletin of Zoology 61 (1), pp. 143-188 : 145

Catapaguroides A. Milne-Edwards & Bouvier, 1892

Catapaguroides A. Milne-Edwards & Bouvier, 1892: 211 (in part); Bouvier, 1922: 26 (in part); de Saint Laurent, 1968 a: 927; McLaughlin, 1997: 454; 2003: 120

Emended diagnosis. –– Gills biserial, no pleurobranch on seventh thoracomere (above arthrobranchs of fourth pereopod); arthrobranchs of third maxilliped occasionally reduced to single or two rudimentary buds or absent, thus gill numbers varying from 8 to 10 pairs. Rostrum as rounded lobe or broadly triangular. Ocular acicles simple. Crista dentata of third maxilliped more or less reduced, no accessory tooth on ischium. Chelipeds unequal, right appreciably stronger. Sixth thoracic sternite with roundly rectangular, subsemicircular, or subtriangular, occasionally armed with spines or tubercles. Fourth pereopod semichelate; propodal rasp with 1 row of corneous scales; no preungual process on dactylus. Fifth pereopod semichelate. Male with short to long sexual tube on coxa of right fifth pereopod, directed from right to left under thorax and recurved anteriorly; coxa of left usually with very short to short tube concealed between 2 thick tufts of setae on eighth thoracic sternite or left sexual tube absent; third to fifth pleopods present. Female with single gonopore on coxa of left third pereopod; pleon with unpaired second to fifth pleopods. Telson without lateral indentations; terminal margins straight or oblique.

Remarks. –– Although the tendency toward reduction and/ or disappearance in the paired arthrobranchs of the third maxilliped, without complete pleurobranch loss, has been reported in Paguridae , i.e., Enneobranchus García-Gómez, 1988 , Enneophyllus McLaughlin, 1997 , Enneopagurus McLaughlin, 1997 , and Pagurus Fabricius, 1775 (García- Gómez, 1988; McLaughlin, 1997; Komai & Osawa, 2001; Siddiqui & Komai, 2008) the loss of those gills with complete loss of pleurobranchs is rarely seen in the family. Indeed, loss of the arthrobranchs of the third maxilliped is the fundamental character to diagnose Enneopagurus , Enneophyllus , and Enneopagurus . Decaphlyllus barunajaya McLaughlin, 1997, represented the unique example of the latter case. During this study, reduction or loss of the arthrobranchs on the third maxilliped is seen in four new species. In Catapaguroides conicus , new species, and C. pusillus , new species, there is only a minute, bud-like arthrobranch above the base of the third maxilliped; no arthrobranchs are found in C. tenuiclavus , new species, and C. tuber , new species. In spite of the reduction of those gills, these four new species fit the generic diagnosis of Catapaguroides . It is reasonable to consider that the loss of the arthrobranchs on the third maxilliped could not be diagnostic alone at genus level.

It has been also found that the left sexual tube is absent in C. tenuiclavus , new species, and C. tuber , new species, though the left coxa has a very short to short sexual tube in other species in general ( McLaughlin, 2003; this study). Male characters still need to be confirmed for C. crassimanus , new species, and C. pusillus , new species.