Comanthus kumi, a new shallow-water comatulid (Echinodermata: Crinoidea: Comatulida: Comasteridae) from the Ryukyu Islands, Japan

Zootaxa ◽  
2012 ◽  
Vol 3367 (1) ◽  
pp. 261 ◽  
Author(s):  
YOSHIHISA FUJITA ◽  
MASAMI OBUCHI

A new species of the genus Comanthus A.H. Clark, 1908, is described on the basis of specimens collected from KumeIsland and Okinawa Island, the Ryukyu Islands, Japan. Comanthus kumi n. sp. is distinguished from all ten congeners byhaving extremely elongate arms exceeding 300 mm in length and the colouration in life. The new species concealed itswhole body in a crevice or small hole on coral reefs during the day and protruded only several elongate arms on the reef surface at night. This habit suggests that the new species is nocturnal.

Zootaxa ◽  
2009 ◽  
Vol 2211 (1) ◽  
pp. 57-68 ◽  
Author(s):  
TOMOYUKI KOMAI ◽  
MASAYUKI OSAWA

A new species of the pagurid hermit crab genus Catapagurus A. Milne-Edwards, 1880, C. insolitus, is described and illustrated based on specimens from shallow waters in Okinawa Island, the Ryukyus. It belongs to an informal species group characterized by the possession of blade-shaped ambulatory dactyli, and is morphologically most similar to C. kosugei (Asakura, 2001). However, the new species is unique within the genus in having a multispinose antennal acicle, rarely seen in species of the family Paguridae.


Zootaxa ◽  
2020 ◽  
Vol 4858 (4) ◽  
pp. 507-520
Author(s):  
TOMOYUKI KOMAI ◽  
ARTHUR ANKER

Manaxius paullus, a new species of axiid burrowing shrimp, is described on the basis of a female holotype from the Society Islands, French Polynesia, and a female paratype from the Ryukyu Islands, Japan. Both specimens were collected on shallow coral reefs. The new species is morphologically closest to five of 17 congeners, viz., M. euophthalmus (de Man, 1905), M. izuensis (Komai, 2011), M. mimasensis (Sakai, 1967), M. poupini (Komai, 2016) and M. supia Poore, 2020, but can be separated from all of them by the rostrum being relatively broad and with one pair of lateral spines, in addition to a pair of supraocular spines; the presence of a subdistal spine on the dorsal margin of the cheliped ischium; the presence of additional three or four small spines on each cheliped palm, adjacent to the dorsal margin; and the lack of a spine near the base of the fingers of each cheliped palm. 


Zootaxa ◽  
2017 ◽  
Vol 4299 (3) ◽  
pp. 405
Author(s):  
TOMOYUKI KOMAI ◽  
HISANORI KOHTSUKA

A new species of the rare caridean genus Bresilia Calman, 1896, B. cinctus, is described and illustrated on the basis of a single ovigerous female specimen collected from Sagami Bay, central Japan, at 218–318 m depth. The new species is morphologically most similar to B. rufioculus Komai & Yamada, 2011, known only from shallow water cave of Ie Island (depths 14–17 m), Okinawa Islands, Ryukyu Islands, but many characters, including the proportionally shorter rostrum, the well developed suborbital lobe of the carapace, and the presence of a spiniform seta on the ventral surface of the pereopod 1 palm, immediately distinguish the new species from B. rufioculus. Bresilia cinctus n. sp. is the first species of the genus known from the Japanese main islands. The discovery of the new species led us to reassess the merit of the informal division of Bresilia proposed by Komai & Yamada (2010). An identification key to the ten named species of Bresilia is presented. 


Zootaxa ◽  
2005 ◽  
Vol 801 (1) ◽  
pp. 1
Author(s):  
TOMOYUKI KOMAI ◽  
MASAYUKI OSAWA

Discovery of a new hermit crab species from the Ryukyu Islands, Japan, led us to reexamine the holotype and supplemental specimens of Trichopagurus trichophthalmus (Forest), the type species of the heretofore monotypic Trichopagurus de Saint Laurent. Our examination has revealed that the gill lamellae of T. trichophthalmus are actually entire (= biserial), rather than shallowly divided distally (= quadriserial) as reported by de Saint Laurent (1970). The new species is assigned to Trichopagurus because of the 11 pairs of biserial gills, well-developed rostrum, moderately long male right sexual tube directed toward exterior, and the possession of a single left gonopore in female. The new species, T. macrochela n. sp., is distinguished from T. trichophthalmus primarily by the dorsoventrally flattened carpus with a distinctly delimited dorsomesial margin, less setose ambulatory legs, and markedly asymmetrical coxae of the female fifth pereopods, of which the left bears numerous setae on the ventral surface. It has been also shown that previous records of T. trichophthalmus from the Palau and Yap Islands are based on both true T. trichophthalmus and T. macrochela. A comparative, updated redescription of T. trichophthalmus is also provided.


Zootaxa ◽  
2006 ◽  
Vol 1168 (1) ◽  
pp. 1 ◽  
Author(s):  
T. KOMAI ◽  
I. YAMASAKI ◽  
S. KOBAYASHI ◽  
T. YAMAMOTO ◽  
S. WATANABE

A new mitten crab species of the genus Eriocheir De Haan, 1835, E. ogasawaraensis n. sp., is described from the Ogasawara Islands, Japan. It is morphologically most similar to E. japonica (De Haan, 1835), found on the Japanese mainland, the Ryukyu Islands, Taiwan, the Russian Far East, Korea and China, but diagnostic is the proportionately broader and dorsally flattened carapace which usually lacks the fourth anterolateral tooth, the ornamentation of the epistome, the male first gonopod and its the coloration. The biology of the new species and the different interpretations concerning the systematics of Eriocheir are briefly discussed.


Zootaxa ◽  
2020 ◽  
Vol 4881 (2) ◽  
pp. 307-322
Author(s):  
TOMOYUKI KOMAI

Two species of the upogebiida mud shrimp genus Gebiacantha Ngoc-Ho, 1989, currently represented by 19 described species, are reported from the Ryukyu Islands, Japan. The first, G. acanthochela (Sakai, 1967), is redescribed in detail based on two female specimens from Amami Islands the second discovered since the original description, enabling better assessment of its diagnostic characters. The second, G. fortispinata n. sp., is described on the basis of a single female holotype from Okinawa Island. It appears closest to G. multispinosa Ngoc-Ho, 1994, known with certainty only from New Caledonia, but the proportionally narrower telson with a more deeply notched posterior margin and the distally unarmed pereopod 3 merus distinguish the new species from G. multispinosa. Three species of Gebiacantha, including G. sagamiensis Komai, 2017, are now known from Japanese waters.


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