We describe Hexapleomera sasuke sp. nov. and provide a supplemental redescription of Hexapleomera urashima Tanabe et al., both of which are based on specimens collected in Japan. Hexapleomera sasuke closely resembles H. urashima, sharing a uropod with four articles, maxillipedal endites with two tiny dorso-subdistal and two distal spiniform setae, a labium with the palp fused to the outer lobe, and the pereopod-1 propodus with an inner subdistal plumose seta. The new species differs from H. urashima in having the basal article of pleopod 3 with three outer plumose setae, the chelipedal carpus with three or four dorsodistal simple setae, the region between the bases of the chelipedal dactylus and fixed finger with three or four simple setae, and deeply pigmented pleopodal rami. We determined partial sequences of the cytochrome c oxidase subunit I (COI) gene (655 nt) from H. sasuke, which proved to be 15.0–15.3% divergent from H. urashima in Kimura 2-parameter (K2P) distance; also in partial sequences of 18S rRNA gene (1888 nt after alignment), 0.8% divergent (K2P distance) was detected between two species. Based on morphology and molecular data, we discuss phylogenetic relationships within Hexapleomera, and propose two morphologically distinct groups, the robusta group and the wombat group.

We describe Hexapleomera urashima sp. nov. from the carapaces of loggerhead sea turtles (Caretta caretta) on Yakushi-ma Island, southwestern Japan, the primary nesting site for the North Pacific population of this turtle. Hexapleomera urashima closely resembles H. edgari Bamber collected from Australian loggerheads (South Pacific population), sharing a uropod with four articles and maxillipedal endites with distal spiniform setae, but differs in having the maxillipedal coxa with two simple setae, the maxillipedal endite with two tiny dorsosubdistal and two distal spiniform setae, the labial palp fused to the outer lobe of the labium, and the basal article of pleopod 3 without inner setae. Several characters (e.g., size or presence/absence of a dorsal triangular process on the male fixed finger; number of inner setae on the pleopodal endopod), assumed to be diagnostic for species in Hexapleomera, actually vary within H. urashima, indicating that reassessment of species diagnoses is warranted. Hexapleomera urashima showed two COI haplotypes differing by one substitution, but separated from representatives of four other genera by 32.2-48.4% K2P distance. Indices of saturation substitution indicated that COI is not useful for phylogeny reconstruction within Tanaididae.

http://zoobank.org/9A02F634-878F-4EA8-BE34-231B95E35DB1 We describe Teleotanais madara sp. nov. from the surfaces of mangrove roots on mudflats at Iriomote Island, Ryukyu Islands, southwestern Japan. This is the first record of any teleotanaid species from the northwestern Pacific. Teleotanais madara resembles T. gerlachi and T. gerlachi sensu Sieg (1976), but differs in having a mid-inner simple seta on antennular article 2, two ventral setae on the basal article of the uropod, the chelipedal fixed finger with one or two ventral simple setae, ventrodistal simple setae on the perepod-1 merus being half as long as the width of the merus, and the dactylus-unguis of pereopods 4-6 articulate. We also present the nucleotide sequence for part of the cytochrome c oxidase subunit I (COI) gene in T. madara for future use in DNA barcoding and phylogeny.

No abstract