Three New Polychaete Species of Platynereis (Annelida, Polychaeta, Nereididae) from Taiwan.

The present study describes three new species of Platynereis Kinberg, 1865 from Taiwan to provide a better understanding of the diversity of Platynereis in the tropical Western Pacific. Platynereis hemeiensis sp. nov. is similar to P. abnormis (Horst, 1924), P. australis (Schmarda, 1861), P. hutchingsae de Leon-Gonzalez, Solis-Weiss and Valadez Rocha, 2001, and P. sinica Sun, Shen and Wu, 1978 in terms of having no notopodial homogomph falcigers in adults. However, P. hemeiensis sp. nov. differs from P. australis by having: 1) fewer transverse rows or diagonal lines in Areas III, IV, VI and VII-VIII (2-3, 6-8, 2 and 2 versus 5, 10, 4 and 4, respectively); 2) tapered dorsal cirri on anterior-most chaetigers (versus stout dorsal cirri); and 3) dorsal cirri always shorter than dorsal ligule in posterior chaetigers (versus always longer than dorsal ligule). Platynereis hemeiensis sp. nov. can be distinguished from P. abnormis and P. sinica by having transverse rows of pectinate paragnaths in Area III (versus no pectinate paragnaths). Platynereis hemeiensis sp. nov. can be readily differentiated from P. hutchingsae by having long-bladed heterogomph spinigers in neuropodia (versus short-bladed heterogomph spinigers). Both P. jihueiensis sp. nov. and P. shihmenensis sp. nov. are somewhat similar to P. bicanaliculata (Baird, 1863), because all have bifid tip of notopodial anchylosed falcigers. However, the two species differ from P. bicanaliculata by having either no pectinate paragnaths or rows of pectinate paragnaths in Area III (versus a broad, oval patch of pectinate paragnaths). Platynereis jihueiensis sp. nov. differs from P. shihmenensis sp. nov. by having: 1) three groups of pectinate paragnaths in Area III (versus no pectinate paragnaths); 2) six to seven transverse rows of pectinate paragnaths in Area IV (versus four transverse rows); 3) three parallel transverse rows of pectinate paragnaths in Area VI (versus three to four non-parallel rows); 4) seven groups of transverse rows of pectinate paragnaths in Areas VII-VIII, middle groups each with three rows and two outer most groups each with one and two paragnaths (versus five groups of transverse rows of pectinate paragnaths, middle groups each with 1-2 rows and two outer most groups each with one paragnath); and 5) each parapodium of chaetigers in anterior, mid-body and posterior regions with three, two and one notopodial homogomph falcigers, respectively (versus each parapodium with one notopodial homogomph falciger in all body regions). A key for identifying Platynereis species from East Asia is provided.

New species and record of Pseudonereis (Annelida, Polychaeta, Nereididae) from Taiwan.

Two new species and one new record species of the genus Pseudonereis are described from specimens collected from ecological surveys of coasts of Taiwan and an offshore island during the past 15 years: P. jihueiensis n. sp., P. kihawensis n. sp., and P. trimaculata. Epitokes of P. jihueiensis n. sp. and P. trimaculata are also described. Pseudonereis jihueiensis n. sp. can be distinguished from congeners by having edentate jaws, -shaped ridge pattern of Areas VIVVI, parapodial morphology (i.e., length ratio of dorsal cirrus to dorsal ligule or presence of small pennant-like dorsal ligule, shape of dorsal ligule in certain region of chaetigers), and no heterogomph spinigers in the subacicular fascicle of the neuropodia. Pseudonereis kihawensis n. sp. differs from congeners by having crescent-shaped pointed-bars in Area VI, -shaped ridge pattern of Areas VIVVI, parapodial morphology (i.e., length ratio of dorsal cirrus to dorsal ligule or presence of small pennant-like dorsal ligule or shape of dorsal ligule in certain region of chaetigers), and no heterogomph spinigers in the subacicular fascicle of the neuropodia. Pseudonereis trimaculata, a species originally described from Indonesia, is reported from Taiwan for the first time. A table of key characters for all species of Pseudonereis is provided.

Additions of new species to the Paratanaoidea (Crustacea, Tanaidacea) of Taiwan.

The present study reports one new species of the Family Leptocheliidae Lang, 1973 and one new species of Pseudotanaidae Sieg, 1976 from Taiwan. The leptocheliid Paraleptochelia setosa sp. nov. can be differentiated from its congeners by both sexes having a two-articled exopod and five-articled endopod on the uropod, the female having coupling hooks on the inner margin of the maxilliped endite, the male having a five-articled antennule flagellum, and cheliped fixed finger with one large subtriangular denticle on the incisive margin in some individuals. The pseudotanaid Akanthinotanais pedecerritulus sp. nov. can be distinguished from its congeners by pereopods 2 and 3 having a sigmoid (S-shaped) dactylus, a unique feature in Akanthinotanais. The family Pseudotanaidae and the two genera are reported from Taiwan for the first time, as are the two genera for the West Pacific. Key morphological characters of all known Paraleptochelia and Akanthinotanais species are tabulated.

Annelids of the eastern Australian abyss collected by the 2017 RV 'Investigator' voyage.

In Australia, the deep-water (bathyal and abyssal) benthic invertebrate fauna is poorly known in comparison with that of shallow (subtidal and shelf) habitats. Benthic fauna from the deep eastern Australian margin was sampled systematically for the first time during 2017 RV 'Investigator' voyage 'Sampling the Abyss'. Box core, Brenke sledge, and beam trawl samples were collected at one-degree intervals from Tasmania, 42°S, to southern Queensland, 24°S, from 900 to 4800 m depth. Annelids collected were identified by taxonomic experts on individual families around the world. A complete list of all identified species is presented, accompanied with brief morphological diagnoses, taxonomic remarks, and colour images. A total of more than 6000 annelid specimens consisting of 50 families (47 Polychaeta, one Echiura, two Sipuncula) and 214 species were recovered. Twenty-seven species were given valid names, 45 were assigned the qualifier cf., 87 the qualifier sp., and 55 species were considered new to science. Geographical ranges of 16 morphospecies extended along the eastern Australian margin to the Great Australian Bight, South Australia; however, these ranges need to be confirmed with genetic data. This work providing critical baseline biodiversity data on an important group of benthic invertebrates from a virtually unknown region of the world's ocean will act as a springboard for future taxonomic and biogeographic studies in the area.

New species and record of xanthid crabs (Crustacean, Decapoda) from Taiwan.

A new species and a new record species of xanthid crabs collected from shallow subtidal hard bottoms of Taiwanese waters are described in the present study. Garthasia ludaoensis n. sp. represents the second species for the genus and can be readily distinguished from the type species, G. americana (Garth, 1939), by having: 1) smaller width to length ratio of the carapace; 2) larger width to length ratio of the third maxilliped; 3) smaller width to length ratio of merus of the third maxilliped; 4) no distinct longitudinal keel on surfaces of sternites 1 and 2; 5) smaller length to width ratio of merus of the last ambulatory leg; 6) smaller width to length ratio of pleonite 2 of the male abdomen; 7) pleonite 2 in semicircular-shaped; 8) a tuft of long setae near distal opening of G1; and 9) distal end of basal segment without upright protrusion of G2. This genus is reported for the first time from Taiwan, as well as from the West Pacific. The second xanthid crab specimen examined in the present study has live colour pattern of the carapace and morphological characters similar to that of Zosimus maculatus (de Man, 1887) described from Ambon, Indonesia (about 3.7° S). The present finding extends the northern distribution range of this species to near 22° N and represents a new record of this species for Taiwan.

Nereis taichungensis nom. nov., a replacement name for Nereis articulata Hsueh, 2020, a junior primary homonym to Nereis articulata Ehlers, 1887.

Nereis articulata Ehlers, 1887 is senior primary homonym to Nereis articulata Hsueh, 2020 from Taiwan. The older Nereis articulata name has been transferred to the genus Ceratonereis Kinberg, 1865 in the subgenus Composetia Hartmann-Schröder, 1985 by Hartmann-Schröder (1985), although this placement may be unreliable (Bakken Wilson, 2005). Nevertheless its original name is an available name and its recombination is in use. Hsueh (2020) mistakenly treated N. articulata Ehlers, 1887 as an unavailable name and described a new Nereis, which possesses articulated tentacular cirri, as Nereis articulata Hsueh, 2020. Nereis articulata Ehlers, 1887 has precedence based on Article 23.4 of the International Code of Zoological Nomenclature (1999). Thus, Nereis taichungensis nom. nov. is named herein as a replacement name for Nereis articulata Hsueh, 2020, a junior primary homonym to N. articulata Ehlers, 1887, and thus permanently invalid (Article 57.2).

New species of Nereis (Annelida, Polychaeta, Nereididae) from Taiwanese waters.

Members of Nereis species are characterised by having conical paragnaths on both maxillary and oral rings of the pharynx, and notopodial homogomph falcigers on posterior chaetigers. The present faunistic study includes Nereis species collected from various ecological surveys on coastal and offshore bathyal benthic habitats of Taiwan. The main results are that eight new species are described: N. articulata n. sp., N. longdongensis n. sp., N. nuwalianensis n. sp., N. paporae n. sp., N. shitipingensis n. sp., N. taitungensis n. sp., N. taiwanensis n. sp. and N. wuchiensis n. sp. In addition, two Nereis species are informally named as sp. A and sp. B because there was only a slightly poorly preserved specimen for each, although each species possess a unique combination of morphological characters that are not known from congeners reported from East Asia. A Table of key characters for all described species in the present study and a key to Nereis species from East Asia are provided.

Two new species of nereidids (Annelida, Polychaeta) from Taiwan.

Two new species of nereidids, Dendronereis chipolini n. sp. and Neanthes hsinchuensis n. sp., collected from brackish aquaculture ponds near coasts of southern Taiwan and fouling community on docks of the Hsinchu fishing port in northwestern Taiwan, respectively, are described in the present study. Dendronereis chipolini n. sp. differs from its congeners by a combination of number and morphology of branchiae, morphology of neuropodia and form of neuropodial homogomph spinigers. Neanthes hsinchuensis n. sp. can be distinguished from congeners reported from East and Southeast Asia by a combination of numbers of conical paragnaths, morphology of notopodia, the absent/present of prechaetal lobe and forms of neuropodial chaetae. A key to Dendronereis species of the world is included, together with a table of morphological characters of Neanthes species reported from East and Southeast Asia, which have no conical paragnaths on Area V of the pharynx.

Neanthes (Annelida: Nereididae) from Taiwanese waters, with description of seven new species and one new species record.

The genus Neanthes is characterised by having conical paragnaths on both maxillary and oral rings of the pharynx and notochaetae all homogomph spinigers. Specimens of Neanthes species collected from various ecological surveys on coastal and offshore waters of Taiwan and coasts of the Kinmen Island during the past 20+ years are examined in the present study. As the result, seven new species are described, one new species record and one undetermined species are also present: N. babuzai n. sp., N. donggungensis n. sp., N. jihueiensis n. sp., N. kaomeiensis n. sp., N. kinmenensis n. sp., N. sanguensis n. sp., N. shigungensis n. sp., N. cf. nanhaiensis Wu, Sun Yang, 1981 and N. sp. 1. Key characters of these species are tabulated. A key to Neanthes species reported from Taiwanese waters is also provided.

A new species of Neorhynchoplax (Crustacea: Decapoda: Brachyura: Hymenosomatidae) from Taiwan.

A new hymenosomatid crab, Neorhynchoplax chipolini sp. nov., is described from Taiwan. Of the 32 known species of Neorhynchoplax, only five other species possess a posterolateral tooth on the carapace and unarmed ambulatory dactyli as in N. chipolini sp. nov.: i.e. N. attenuipes (Chopra Das, 1930), N. falcifera Naruse, Mendoza Ng, 2008, N. sinensis (Shen, 1932), N. tuberculata (Chopra Das, 1930), and N. venusta Ng, 2015. Neorhynchoplax chipolini sp. nov., however, differs from these congeners by having the median rostral tooth distinctly bent downwards and the presence of a tubercle on the inner anterolateral margin of the first exopod article of the third maxilliped. Brood size, egg diameters, and the protective structure of eggs in N. chipolini sp. nov. are noted. A table for the habitat preferences of all known species of Neorhynchoplax is provided.

First records of Composetia, Eunereis and Nectoneanthes (Annelida: Nereididae) from Taiwan, with descriptions of two new species.

Three species of nereidids collected from various ecological surveys conducted on coasts of west central and northeastern of Taiwan are studied. Each species represents a genus in the subfamily Nereidinae Blainville, 1818 not previously reported from Taiwan: Composetia Hartmann-Schröder, 1985, Eunereis Malmgren, 1865 and Nectoneanthes Sato, 2013. Composetia budaiensis n. sp. can be distinguished from congeners by having 2-5 and 17-27 paragnaths on Areas I III of the pharynx, respectively. Eunereis shichengensis n. sp. differs from congeners by having one shield-shaped bar on Area VI of the pharynx. The generic diagnosis of Eunereis is emended slightly to include short neuropodial heterogomph falcigers in E. shichengensis n. sp. and three other congeners. Nectoneanthes species examined in the present study showed a continuous broad band of numerous paragnaths on the oral ring of the pharynx, which agrees with the unique character of N. uchiwa Sato, 2013 and represents the first record of the species for Taiwan. A key to all known species to Eunereis are provided.

Additions of new species to Thelepus (Thelepodidae), with description of a new Terebellides (Trichobranchidae) from Taiwan.

Following a recent report on two new species of Thelepus for the Taiwan, we describe two more new species, T. hemeiensis sp. nov. and T. wuchiensis sp. nov., for the genus. In addition, a new species of the Family Trichobranchidae is also described, Terebellides baliensis sp. nov., which was collected from an offshore monitoring survey in northwestern Taiwan. The genus Terebellides as well as the Family Trichobranchidae are reported for the first time from Taiwanese waters.

New species of Thelepodidae (Terebelliformia, Polychaeta) from Taiwan.

Four new species of thelepodid polychaetes are reported from Taiwan, Streblosoma chiguensis sp. nov., Streblosoma wuchiensis sp. nov., Thelepus taiwanensis sp. nov., Thelepus longtongensis sp. nov. The family Thelepodidae, as well as the two genera Streblosoma and Thelepus, is reported for the first time from Taiwanese waters. A synoptic table, including number of branchial filaments on segments 2 to 4, the presence/absence of eyespots, number of pairs of notopodia, uncinial dental formula of anterior and posterior tori, and type locality, is provided for all species of Thelepus.

Additions of new species and records to the Tanaidomorpha (Crustacea: Tanaidacea) of Taiwan.

This study reports two new species and one new species record of tanaidomorphan tanaidaceans from Taiwan. The leptocheliid Leptochelia taitungensis sp. nov. can be separated from the most similar species, Leptochelia tarda, in the Leptochelia dubia/savignyi group by having long distal spines on the maxilliped endites and the male having two-articled uropod exopods. The tanaidid Zeuxo shitipingensis sp. nov. can be distinguished from Z. normani in the Zeuxo normani species-complex by having a triangular left mandible lacinia mobilis, only one seta on the pleopod endopod inner margin, and the uropod endopod with five to six articles in most adult specimens. Morphological comparisons between Leptochelia taitungensis sp. nov. and its congeners within the dubia/savignyi group, as well as between Zeuxo shitipingensis sp. nov. and its congeners, are tabulated.

New species and records of Apseudomorpha (Crustacea: Tanaidacea) from Taiwan.

The present study reports the first record of Apseudomorpha from Taiwan and includes descriptions of three new species and one new species record. Paradoxapseudes pangcahi sp. nov. differs from the most similar congener, Paradoxapseudes littoralis, by having one segment less in the antennal flagellum and fewer segments in the uropod endopod. Pseudoapseudomorpha tagopilosus sp. nov. is distinguished from its most similar congener, Pseudoapseudomorpha ornata, by having one long lateral seta on pleonite 4, a four-segmented antennular outer flagellum, and a male with smaller and thinner 'small' cheliped than that of the female and with vestigial pleopods on pleonite 3. Indoapseudes multituberculata sp. nov. stands out from its congeners by having pleopods only on the last two pleonites in females, many small tubercles terminally on the pleotelson, and mandibular palp article 1 with noticeable distal teeth. The Synapseudes species recorded in the present study morphologically agrees with Synapseudes hansmuelleri that was originally described from the Tioman Archipelago, Malaysia, South China Sea. Morphological comparisons between each of the three newly described species and its congeners are tabulated. 

Two new species of Tanaidacea (Crustacea, Peracarida) from Taiwan.

Two new species, representing the genus Aparatanais of the family Paratanaidae and the genus Tanais of the family Tanaidae (both families belonging to the suborder Tanaidomorpha), are described in the present study. The genus Aparatanais, the family Paratanaidae and the superfamily Paratanaoidea are recorded for the first time from Taiwan. Aparatanais lenoprimorum sp. nov. departs from its congeners by the lack of subdistal teeth on the superior margin of the right mandible and without serration on left mandible lacinia mobilis. Tanais nuwalianensis sp. nov. is distinguished from its most similar congener, Tanais tinhauae, by the presence of a much smaller right mandible lacinia mobilis, fewer carpal spines on pereopods 2-6, fewer leaf-like setae on the distal margin of the propodus of Pereopod 6, and fewer inner setae on the pleopod basis. Morphological comparisons between members of the genus Aparatanais, as well as the genus Tanais are tabulated.

New species and new records of eunicids (Polychaeta, Eunicidae) from Taiwan.

Seven species of eunicids were found from rocky intertidal and shallow subtidal habitats on the coasts of Taiwan. These polychaetous worms belong to two genera, Eunice Cuvier, 1817 and Nicidion Kinberg, 1865. Among them, five species are new to science, namely Eunice jihueiensis sp. nov., Eunice reticulata sp. nov., Eunice shihmenensis sp. nov., Eunice taoi sp. nov., and Nicidion megabalanicola sp. nov., Eunice annulicirrata Miura, 1986 and Eunice dilatata Grube, 1877, are documented for the first time from this geographic region. A key to the genus and species of these eunicids is provided.