Xenocheira pirloti Moore, 1988

Hughes, Lauren Elizabeth, 2017, Review of Xenocheira Haswell, 1879 (Crustacea: Amphipoda: Aoridae), Records of the Australian Museum 69 (4), pp. 223-236 : 231

Xenocheira pirloti Moore, 1988

Figs 7–10

Xenocheira fasciata . — PirlOT, 1938: 335, fiG. 150. Xenocheira pirloti Moore, 1988: 718 .

Type material. Stat. 273, Pulu Jedan , Aru Islands [Iles Aru], 23–26 December 1899 , shell sand [sable coquillier], 13 m, 3 males. (Material not found, pers. comm. K. Van Dorp January 2016)

Material examined. Northern Territory, Australia: 1 a male, 7 mm, dissected, 1 slide, NTM Cr 018973; 1 b male, 7.1 mm, dissected, 1 slide, NTM Cr 018974; 1 c male, 8 mm, dissected, 1 slide, NTM Cr 018975; 1 d male, 9 mm, dissected, 1 slide, NTM Cr 018976.; 1 e female, 9.2 mm, dissected, 1 slide, NTM Cr 018977; 1 f female, 5.4 mm, dissected, 1 slide, NTM Cr 018978; 1 g female, 5 mm, dissected, 1 slide, NTM Cr 018979; 12 specimens (4 male and 6 females), NTM Cr 015901, Dawson Rock , Bynoe Harbour , 12°42'17.38"S 130°35'33.42"E, 12 m, sponge sample, 9 June 2003, coll. B. Glasby et al .. 1 male and 4 females, NTM Cr015886, Table Head, Port Essington , 11°13'30"S 132°10'30"E, algae and reef rock, 14 May 1983; 3 male and 2 female specimens, NTM Cr 011679, north of Oliver Reef, Vernon Islands, Beagle Gulf, 12°1.02'S 130°58.86'E, 30 m, rocky bottom, 11 October 1993, coll. K. E. Coombes, FV Kunmunyah (Beagle Gulf Marine Park Survey) .

Western Australia: 1 male, 12 mm, and 1 female, 13.2 mm, WAM C27165, Dampier Archipelago, 20°41'S 116°33'E, 23 July 1999, coll. S. Slack-Smith (DA2/99/68) .

Variation. With increasing size, the male gnathopod 1 propodus becomes less elongate and more bulbous, as the posterior margin reduces and the anterior margin becomes more convex ( Fig. 8 ).

Remarks. PirlOT (1936) idenTified 3 specimens frOm The ArU Islands as Xenocheira fasciata Haswell, 1879 . Based on Pirlot’s illustrations of gnathopods 1 and 2, Moore (1988) considered the variation in gnathopod 1 propodus length siGnificanTlY differenT frOm X. fasciata and established the new species name X. pirloti for the Aru Islands material without examining Pirlot’s original specimens. Pirlot’s material from the Siboga Expedition is currently held by the Department Invertebrates, Naturalis Biodiversity Center, Leiden, The Netherlands. Recent contact with the curator for Crustacea, Chelicerata and Myriapoda Karen Van DOrp cOnfirmed ThaT The TYpe maTerial (eiTher slide Or wet preparations) of X. pirloti could not be located and for now is considered presumed lost.

Assessment of a large set of tropical Australia collections of Xenocheira pirloti included large adult males, gravid females and a range of smaller specimens has revealed the Aru Islands material are juvenile specimens of indeterminate sex and not adult males. A growth series of material is presented here to demonstrate the full development range of X. pirloti . This present description of additional material of X. pirloti supports this species as distinct from X. fasciata . Xenocheira pirloti is known from tropical waters in northern Australia and the Banda Sea in the Indonesian Archipelago while X. fasciata occurs in temperate waters along east coast and southern Australia including Tasmania.

Xenocheira pirloti is most similar to X. fasciata in the male gnathopod 1 propodus palm with sinus. Xenocheira pirloti has an acute gnathopod 1 propodus palm while X. fasciata has an obtuse palm. See also remarks for X. fasciata . Distribution. Indonesia: Pulu Jedan, Aru Islands (Pirlot, 1936). Australia. Northern Territory: Beagle Gulf, Port Essington, Bynoe Harbour, Dampier Archipelago (current study).

Figures

Figure 7. Xenocheira pirloti Moore, 1988, male, 9 mm, NTM Cr018976, Dawson Rock, Bynoe Harbour, Northern Territory (scale 0.1 mm).

Figure 8. Xenocheira pirloti Moore, 1988, male, 7.0 mm, NTM Cr018973, male*, 7.1 mm, NTM Cr018974, male**, 8 mm, NTM Cr018975,male***, 9 mm, NTM Cr018976, Dawson Rock,Bynoe Harbour, Northern Territory (scale 0.1 mm).

Figure 9.Xenocheira pirlotiMoore,1988, d male, 9 mm, NTM Cr018976, Dawson Rock, BynoeHarbour, NorthernTerritory (scale 0.1 mm).

Figure 10. Xenocheira pirloti Moore, 1988, e female, 9.2 mm, NTM Cr018977, DawsonRock,Bynoe Harbour, NorthernTerritory (scale 0.1 mm).