Paguristione uniuropodus, a new genus and a new species of Pseudioninae infesting hermit crabs from China (Crustacea, Isopoda, Bopyridae).

Paguristione uniuropodus gen. n., sp. n. infests Paguristes sp. in the East China Sea. Paguristione gen. n. differs from the closely related genera Pseudione and Pagurion by its females having indistinct lateral plates on the last two pleomeres and its male with a long tapering pleon of six pleomeres, lacking both pleopoda and uropoda.

Introduction

Bopyrid isopods infesting hermit crabs belong to the subfamilies (branchial parasites) and (dorsoabdominal parasites). An, Markham and Yu (2010), An, Williams and Yu (2011) and An, Li and Markham (2013) have reported a total of eight bopyrid species infesting hermit crabs in the South China Sea. Markham (1992) recorded six species of bopyrids infesting hermit crabs in Hong Kong. Boyko (2004) PageBreakreported one such species from Taiwan. In Chinese waters as a whole, An (2006) reported ten species of bopyrids infesting hermit crabs. Currently, throughout Asia, 36 species are recorded infesting 48 hermit crabs from Asia (Table 1). Worldwide, McDermott, Williams and Boyko (2010) catalog 83 species of bopyrids infesting hermit crabs, of which 41 species in ten genera are branchial parasites. As hosts worldwide, 11 species of are known to bear bopyrids (Table 2); their parasites, all branchially infesting members of the subfamily , are in the genera , , and now the new genus .

Table 1.

Bopyrid isopods infesting hermit crabs in Asian waters.

Bopyrids	Hosts	Localities	References
Subfamily Pseudioninae
Asymmetrione asymmetrica (Shiino, 1933)	Clibanarius bimaculatus (De Haan, 1849)	Japan	Shiino 1933
	Clibanarius merguiensis de Man, 1888	Thailand	Markham 1985a; Brunenmeister 1980
Asymmetrione sallyae Williams & Schuerlein, 2005	Diogenes avarus Heller, 1865	Singapore	Williams and Schuerlein 2005
Bopyrissa dawydoffi (Codreanu & Codreanu, 1963)	Clibanarius merguiensis de Man, 1888	Vietnam	Codreanu and Codreanu 1963
Bopyrissa liberorum Markham, 1985	Clibanarius merguiensis de Man, 1888	Thailand	Markham 1985a
Bopyrissa pyriforma (Shiino, 1958)	Clibanarius bimaculatus (De Haan, 1849)	Hong Kong	Markham 1982
	Diogenes edwardsii (De Haan, 1849)	Japan	Shiino 1958
Bopyrophryxus branchiabdominalis Codreanu, 1965	Oncopagurus monstrosus (Alcock, 1894)	Indonesia	Bourdon and Boyko 2005
	Paragiopagurus acutus (de Saint Laurent, 1972)	Philippines	Bourdon and Boyko 2005
	unidentified pagurid	Indonesia	Bourdon and Boyko 2005
Pagurion arrosor An, Li & Markham, 2013	Dardanus arrosor (Herbst, 1796)	China	An, Li and Markham 2013
Pagurion tuberculata Shiino, 1933	Dardanus scutellatus (H. Milne Edwards, 1848)	Japan	Shiino 1933
	Dardanus aspersus (Berthold, 1846)	China	An, Li and Markham 2013
Pagurocryptella holthuisi Boyko & Williams, 2010	Solitariopagurus tuerkayi McLaughlin, 1997	Japan	Boyko and Williams 2010
Parapagurion calcinicola Shiino, 1933	Calcinus elegans (H.Milne Edwards, 1836)	Japan	Shiino 1933
	Calcinus linapropodus Morgan & Forest, 1991	Japan	Shiino 1933
	Paguristes monoporus Morgan, 1987	Indonesia	Haig and Ball 1988
	Paguristes sp.	Thailand	Markham 1985a
	Pagurus aff. hedleyi or kulkarnii	Hong Kong	Markham 1992
Parapseudione lata Shiino, 1958	Pagurus middendorffii Brandt, 1851	Japan	Shiino 1958
Propseudione rhombicosoma Shiino, 1933	Calcinus laevimanus (Randall, 1840)	Japan	Shiino 1933
	Calcinus morgani Rahayu & Forest, 1999	Japan	Shiino 1933
Pseudione calcinii Shiino, 1958	Calcinus latens (Randall, 1840)	Japan	Shiino 1958
Pseudione clibanaricola Shiino, 1933	Clibanarius bimaculatus (De Haan, 1849)	Japan	Shiino 1933
Pseudione hyndmanni (Bate & Westwood, 1868)	Pagurus sp.	Japan	Shiino 1936
Pseudione intermedia Nierstrasz & Brender à Brandis, 1932	Lophopagurus (Australeremus) triserratus (Ortmann, 1892)	Japan	Shiino 1936
	Pagurus sp. ?	Japan	Nierstrasz and Brender à Brandis 1932
Pseudione kensleyi Williams & Schuerlein, 2005	Clibanarius infraspinatus Hilgendorf, 1869	Singapore	Williams and Schuerlein 2005
Pseudione nobili Nierstrasz & Brender à Brandis, 1923	Trizocheles spinosus spinosus (Henderson, 1888)	Indonesia	Nierstrasz and Brender à Brandis 1923
Pseudionella attenuata Shiino, 1949	Pagurus sp.	Japan	Shiino 1949
Pseudionella spiropaguri An, Li & Markham, 2013	Spiropagurus profundorum Alcock, 1905	China	An, Li and Markham 2013
	Spiropagurus spiriger (De Haan, 1849)	China	An, Li and Markham 2013
Parasymmetrione tuberculineata An, Markham & Yu, 2010	Clibanarius corallinus (H. Milne-Edwards, 1848)	South China Sea	An, Markham and Yu 2010
Asymmetrione globifera An, Markham & Yu, 2010	Dardanus hessii (Miers, 1884)	Beibu Gulf	An, Markham and Yu 2010
	Spiropagurus sp.	South China Sea	An, Markham and Yu 2010
Subfamily Athelginae
Allathelges pakistanensis Kazmi & Markham, 1999	Paguristes perspicax Nobili, 1906	Pakistan	Kazmi and Markham 1999
Athelges akanoshimensis var. tenuibranchiatus Shiino, 1936	Lophopagurus (Australeremus) triserratus (Ortmann, 1892)	Japan	Shiino 1936
Athelges japonicus Shiino, 1958	Pagurus constans (Stimpson, 1858)	Japan	Shiino 1958
	Pagurus lanuginosus De Haan, 1849	Japan	Shiino 1958
	Pagurus middendorffii Brandt, 1851	Japan	Shiino 1958
Athelges sp.	Trizopagurus strigatus (Herbst, 1804)	Indonesia	Haig and Ball 1988

Table 2.

Known bopyrids infesting species with localities and references.

Bopyrids	Host	Type locality	References
Asymmetrione aequalis Pardo, Boyko & Mantelatto, 2009	Paguristes tomentosus H. Milne Edwards, 1848	Peru	Pardo et al. 2009
Asymmetrione desultor Markham, 1975	Pagurus tortugae Schmitt, 1933	Brazil	Bourdon 1979
Asymmetrione foresti (Bourdon, 1968)	Paguristes eremita (Linnaeus, 1767)	Mediterranean	Bourdon 1968
Parapagurion calcinicola Shiino, 1933	Paguristes monoporus Morgan, 1987	Indonesia	Haig and Ball 1988
	Pagurus sp.	Thailand	Markham 1985a
Parapagurion imbricata Markham, 1978	Pagurus tortugae Schmitt, 1933	Cuba	Markham 1978
Pseudione biacuta Bourdon, 1979	Paguristes robustus Forest & de Saint Laurent, 1967	Uruguay	Bourdon 1979
Pseudione quasimodo Boyko & Williams, 2004	Paguristes grayi Benedict, 1901	Bahamas	Boyko and Williams 2004
	Paguristes invisisacculus McLaughlin & Provenzano, 1974	Bahamas	Boyko and Williams 2004
	Paguristes anahuachis Glassell, 1938	Gulf of California	Brusca 1980
Allathelges pakistanensis Kazmi & Markham, 1999	Paguristes perspicax Nobili, 1906	Pakistan	Kazmi and Markham 1999
Athelges pelagosae Babiç, 1912	Paguristes eremita (Linnaeus, 1767)	Adriatic	Babiç 1912
Parathelges piriformis Markham, 1972	Paguristes oxyophthalmus Holthuis, 1959	Colombia	Markham 1978
Parathelges whiteleggei Nierstrasz & Brender à Brandis, 1931	Paguristes monoporus Morgan, 1987	Indonesia	Haig and Ball 1988
Pseudostegias otagoensis Page, 1985	Pagurus barbatus (Heller, 1862)	New Zealand	Page 1985

Specimens used in this study were collected from the East China Sea in 1958, and one of the authors (An 2006) examined the parasites and reported sp. n. infesting sp. in her doctoral dissertation (not a published work in the sense of the ICZN). Further examination shows that they represent a new species in a new genus. The name is here entered into its synonymy.

Material and methods

Materials for this study originated from Chinese Comprehensive Oceanographic Survey. All materials examined have been deposited in the . Specimens were viewed and drawn using a Zeiss Stemi SV Apo microscope.

Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China

Taxonomy

Family Rafinesque-Schmaltz, 1815Subfamily R. Codreanu, 1967

gen. n.

http://zoobank.org/1076C4FA-D580-45AC-A918-B28C2D1FC396

Diagnosis.

Female. All body segments distinct, almost symmetry. Rudimentary coxal plates present in first four segments. Marsupium complete. Oostegite 1 with simple tubercules on internal ridge. Palp of maxilliped with long setae. All pleomeres distinct. First three pleomeres with lateral plates and biramous pleopoda. Fourth and fifth pleomeres with biramous pleopoda, but lateral plates without lateral plates. Sixth pleomere without lateral plates, uropoda uniramous. Male. All segments distinct. First and last pereomeres respectively much broader than adjacent head and first pleomere. Pereopods of first pair smaller than those of following 3 pairs. Pleon elongate, of 6 distinct pleomeres. No pleopoda or uropoda.

Etymology.

Combination of the genus name of its host, and bopyrid genus name . Gender feminine.

Type species.

sp. n., herein designated.

sp. n.

http://zoobank.org/E7EECB56-131C-4682-825B-1CBE50B12DCE

Fig. 1

Figure 1.

sp. n. A–I holotype female J–N allotype male. A Dorsal view B Ventral view C Left antennae D Right maxilliped, external view E Palp of right maxilliped F Left side of barbula G Right oostegite 1, external view H Right oostegite 1, internal view I Pereopod 4 J Dorsal view K Ventral view L Left antennae M Pereopod 2 N Pereopod 7. Scale: 1.00 mm (A, B); 0.36 mm (D); 0.17 mm (C, E); 0.50 mm (F–I); 0.47 mm (J, K); 0.23 mm (L–M).

An, 2006 (unpublished thesis): 30–31, fig. 8 (invalid name).

Material examined.

Infesting sp. Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China (IOCAS). Chinese Comprehensive Oceanographic Survey, East China Sea, Station 4081, 28°00'N, 128°30'E, 74m, 5 April 1958, Yulin Liao, coll. Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China (IOCAS). 1♀ holotype, CIEA408101; 1 ♂, allotype, CIEA408102.

Description of holotype female.

Length 5.20 mm, maximal width 3.41 mm across third pereomere, head length 1.0 mm, head width 1.31 mm. Body distorted about 16° (Fig. 1A).

Head subelliptical, fully embedded in pereomere 1, with short frontal lamina completely across anterior margin. Eyes absent (Fig. 1A). Antennae with two articles and three articles respectively (Fig. 1C). Maxilliped (Fig. 1D, E) with prominent round articulating palp, that fringed on medial margin by sparse setae. Plectron short and blunt. Barbula (Fig. 1F) with 2 large sharp falcate projections on each side, medially unornamented.

Pereon broadest across third pereomere. First 3 pereomeres with coxal plates. Brood pouch completely enclosed by oostegites. First oostegite (Fig. 1G, H) with deep groove separating 2 articles externally; internal ridge bearing 4-7 simple projections; posterolateral point extending laterally. Pereopods rudimentary, not extending beyond margins of brood pouch, visible only ventrally; all pereopods with all articles distinct, of nearly same size and structure (Fig. 1I).

Pleon of 6 distinct pleomeres, first three produced into small lateral plates and bearing biramous pleopods; fourth and fifth pleomeres lacking lateral plates. Terminal pleomere greatly reduced and deeply embedded in fifth, bearing uniramous uropoda. All pleopodal rami produced into tapering points and progressively smaller posteriorly, extending to sides of pleon and leaving ventral surface of pleon uncovered.

Description of allotype male

Body outline suboval. Length 2.52 mm, maximal width across third pereomere, 1.05 mm, head length 0.30 mm, head width 0.42 mm, first pleomere width 0.50 mm, fifth width 0.20 mm. All segments distinct (Fig. 1J, K).

Head semicircular, broader than long, much narrower than first pereomere, distinctly separated from first pereomere and not at all embedded into it (Fig. 1J). Eyes absent. Antennae visible only ventrally, not extending to margins of head, of 3 and 4 articles respectively; second antenna with sparse short setae on terminal article (Fig. 1L).

Pereon smoothly rounded, slightly broadest across third pereomere. No midventral tubercles. All pereopods with all articles distinct. Pereopod 1 somewhat smaller than pereopods 2-4, those 3 pairs largest and all of about same size; pereopods 5-7 progressively smaller (Fig. 1M, N). Pereopods 1-4 bearing sharp extended dactyli, dactyli of pereopods 5-7 much reduced.

Pleon elongate, extending far posteriorly, of 6 distinct pleomeres deeply separated laterally, each markedly narrower than that before it; pleomere 1 abruptly narrower than last pereomere, it and pleomere 2 much shorter than pleomeres 2-6; every pleomere broadest across posterior edge. Pleopods and uropods completely absent, not even indicated by scars.

Latin noun uniuropodus, referring to the uniramous uropoda of the female, used in apposition.

Remarks.

The new genus differs from other closely similar hermit-crab-infesting genera , and thus: female with only rudimentary pleonal lateral plates (only first three pleomeres with small lateral plates) and uniramous uropoda, male with head and pleon abruptly narrower than contiguous pereomeres, first pereopod smaller than pereopods 2-4 and pleopodal appendages completely lacking. Females of have distinct pleonal lateral plates on pleomeres 1-5; its males have pleopods, and their heads and pleons are smoothly narrower than the pereon. Females of have distinct lamellar pleopodal appendages on all pleomeres PageBreak1-6 and biramous uropoda; its males have equally width pereopods and uniramous pleopods. Females of are nearly symmetrical and bear well-developed lateral plates on pleomeres 1-5 and uniramous uropods; the first pereopods of the males are never smaller than the second ones.