Axiopsis pica Kensley, 2003

Figure 1d, e

Axiopsis pica Kensley, 2003: 363, figs 1, 2, pl. 1.— Ngoc-Ho, 2005: 51–55, fig. 2.

Axiopsis serratifrons .— Sakai, 2011: 56–63 (part).

Material examined. Papua New Guinea. Madang Province, PAPUA NIUGINI stations. Kranket I., outer slope, 05° 11.3' S, 145° 49.5' E, 1–24 m (stn PR129), IU-2013-7048 (female, 14.4 mm) .

Mariana Islands. Guam Island, Apra Harbour, Middle Shoal, among coral rubble and rocks, 1 m, IU- 2016-8007 (UF 2782), (1 ovigerous female, 16 mm); near Harbour entrance, among rocks, 8–12 m, IU- 2016-8008 (UF 3021) (female, 13.5 mm).

Distribution. Guam (type locality), Papua New Guinea, French Polynesia; to 24 m depth.

Remarks. The single female from Papua New Guinea was first identified by its striking colour pattern, similar to that published by Kensley (2003: pl. 1). Kensley (2003) noted that, as well as a distinctive colour, Axiopsis pica has ‘a broader and more robust larger cheliped of pereopod 1 bearing flattened scale-like tubercles’ than A. serratifrons with which it co-occurred. The upper margin of the propodus of the holotype and of the Papua New Guinea female is 1.5 times its greatest height. Kensley (2003) also compared his new species with material identified as A. serratifrons from Hawaii which has more slender chelipeds.

Ngoc-Ho (2005) compared specimens that she identified as A. pica from French Polynesia with a syntype of A. serratifrons also from Hawaii. The major cheliped of this syntype is twice as long as wide and smooth. Following Sakai’s (2011) selection of the other syntype from Tonga as the lectotype (see below), comparison with Hawaiian specimens may be irrelevant.

Axiopsis pica co-occurs with A. serratifrons in both French Polynesia and Papua New Guinea. The major cheliped of the largest specimen is similarly proportioned, 1.5 times as long as wide, as of similarly-sized A. serratifrons . The most reliable morphological distinction between the two species can be found in the carapace. The carapace and pleon of A. serratifrons is smooth and flexible, with few scattered long setae, while that of A. pica is sclerotised, almost calcified and pitted with short stiff setae associated with the pits (Fig. 1d).

Axiopsis serratifrons (A. Milne-Edwards, 1873)

Figs 1f–i, 6a

Axia serratifrons A. Milne-Edwards, 1873: 263, pl. 13 figs 6, 6a.

Axiopsis serratifrons .— Sendler, 1923: 44, pl. 21 fig. 10.— Sakai and de Saint Laurent, 1989: 76.— Sakai, 2011: 56–63, fig. 9 (extended synonymy).

Material examined. Paralectotype. Hawaii, IU-2016-8115 (Th147) (male, 10 mm) .

Papua New Guinea. Madang Province, PAPUA NIUGINI stations. Kranket I., outer slope, 05° 12.1' S, 145° 49.3' E, 17 m (stn PB02), IU-2013-302 (female, 9.3 mm); 05° 11.3' S, 145° 49.5' E, 1–11 m (stn PR225), IU-2013-7051 (male, 22 mm), NMV J71638 (ovigerous female, 22 mm); 05° 12' S, 145° 49' E, 10 m (stn PR99), IU-2013-7033 (ovigerous female, 9.5 mm). Rempi Area, S of Barag I., 05° 01.3' S, 145° 47.9' E, 2–13 m (stn PR61), IU-2013-638 (ovigerous female, 9.3 mm); S of lagoon inside bay, 05° 01.6' S, 145° 48.1' E, 2–15 m (stn PR69), IU-2013-7116 (male, 4.3 mm); outer slope, 05° 01.6' S, 145° 48.1' E (stn PR65), IU-2013-637 (male, 11.5 mm). Alexishafen, 05° 05.3' S, 145° 48.1' E, 1–6 m (stn PD31, IU-2013-7019 (male, 6.3 mm). W of Panab I., 05° 10.3' S, 145° 48.5' E, 1–18 m (stn PR147), IU-2013-7052 (female, 15.8 mm). Riwo waters, 3–15 m (stn PR109), IU-2013-7061 (male, 11.9 mm). S of Yabob I., 05° 15.5' S, 145° 47.3' E, 2–6 m (stn PD66), IU-2013-7098 (male, 5.8 mm). Ulimal I., 05° 05.6'S, 145° 48.7' E, 6 m (stn PS16), IU-2013-15308 (male, 10.0 mm) .

New Ireland Province, Kavieng region, KAVIENG 2014 stations. Edmago I., 02° 36.9' S, 150° 44.4' E, 9 m (KZ2), IU-2014-826 (male, 8.6 mm); IU-2014-2685 (male, 9.3 mm). New Ireland mainland near N Cape, 02° 33.3' S, 150° 47.7' E, 1–20 m (stn KZ18), IU-2016-1011 (female, 12.5 mm). W side of Edmago I., 02° 37.1' S, 150° 44.2' E, 5–6 m (stn KZ20), NMV J71639 (ovigerous female, 10.5 mm). E side of Ral I., 02° 36.7' S, 150° 42.6' E, 3–10 m (stn KZ22), IU-2014-1090 (female, 10.6 mm). Byron Channel, SE Patio I., 02° 36.6' S, 150° 32.9' E, 2–7 m (stn KB40), IU-2014-2577 (ovigerous female, 10.9 mm). NE of Big Nusa I., entrance to Kavieng Harbour, 02° 33.7' S, 150° 49.1' E, 10 m (stn KZ11), IU-2014-2625 (ovigerous female, 10.6 mm). Mouth of Albatross Passage, E side, 02° 35.2' S, 150° 43.1' E, 13 m (KB72), IU-2016-8136 (juv., 5.0 mm). Between Big Nusa and Little Nusa Islands, 02° 34.6' S, 150° 46.3' E, 13-14 m (KB16), IU-2014-17688 (female, 6.9 mm). Eickstedt Passage W of Usien I., 02° 40.3' S, 150° 39.1' E, 9–11 m (KR70), IU-2014-17691 (male, 13.6 mm). Albatross Passage, 02° 44.6' S, 150° 42.8' E, 12–15 m (KD12), IU-2014-17692 (juv., 3.6 mm) .

Colour. Variable. Generally reddish-orange, stronger colour on gastric carina; pleonal pleura with white patch anteroventrally; chelipeds similar or steel-blue, colour stronger at base of fingers (see figs 1f–i and Kensley [1981]).

Distribution. Widespread in the Indo West-Pacific, eastern Pacific (Hendrickx, 2008), south-west Atlantic (Sakai, 2011, 2015) and south-east Atlantic (Wirtz, 2009); subtidal.

Remarks. Of the two syntypic specimens from Samoa and Hawaii recorded by A. Milne-Edwards (1873), Sakai (2011) selected that from Samoa as the lectotype, not the one from Hawaii erroneously applied to the ‘type locality’ by Kensley (2003) and called ‘holotype’ by Ngoc-Ho (2005). This confusion was discussed by Komai and Tachikawa (2008). Sakai’s (2011: figs 8A, B, 9) illustrations of the Samoan lectotype (ZMB K8405: checked for me by A. Brandt) are indistinguishable from Ngoc-Ho’s (2005: fig. 3) of the Hawaiian paralectotype (MNHN IU- 2016-8115 [Th147]). Sakai’s (2011: fig. 8C) illustration of the Hawaiian paralectotype differs from both in appearing to have larger rostral teeth, the rostrum less evenly tapering, more teeth on the median carina (shown by my re-examination to have two on the rostrum, c. 15 on gastric region; fig. 6a), almost no spines on the lateral gastric carina (actually 13, 15), and fewer intermediate gastric tubercles (actually c. 20). The cheliped of the paralectotype lacks tuberculation on the propodal faces and the spine on the upper border of the merus, but these absences are common in juveniles of this size.

In an extensive synonymy, Sakai (2011) synonymised four species with A. serratifrons . The synonymy of Axius affinis De Man, 1888 (type locality, Ambon, Indonesia), Axiopsis sculptimana Ward, 1942 (type locality, Diego Garcia, Chagos Archipelago) and Axiopsis brasiliensis Coelho and Ramos-Porto, 1991, has not been disputed although a species with such a wide distribution suggests further examination is warranted as Komai and Tachikawa (2008) suspected. Kensley (1981) discussed the species in the Americas but his synonymy was limited. Ngoc-Ho (2005) recognised A. pica Kensley, 2003 (type locality, Guam), the fourth species synonymised by Sakai (2011), following a detailed justification and recorded it from French Polynesia. This synonymy is not recognised here (see A. pica above for discussion of differences).

Sakai’s (2011) key to species of Axiopsis relied on the presence of a tooth on the upper margin of the merus and a smooth propodus of the cheliped to distinguish A. consobrina from A. serratifrons (without a tooth, with squamose propodus). Many smaller individuals, including ovigerous females, identifiable as A. serratifrons based on colour resemble A. consobrina De Man, 1905 in these features. De Man (1905) distinguished A. consobrina on the absence of intermediate gastric teeth between the carinae and the palm of the smaller cheliped as long as the fingers but this is true only for the type. Axiopsis consobrina occurs usually from 75 m to a maximum of 310 m depth (Sakai, 2011; Vaitheeswaran, 2014) but Ngoc-Ho (2005) recorded one individual from 2.5 m depth. Axiopsis serratifrons is more immediately subtidal.