Mucrollichirus mucronatus ( Strahl, 1862 )

Poore, Gary C. B., 2023, New records and one new species of Callichiridae (Crustacea, Axiidea) from the Indo-West Pacific, with keys to species of Corallianassa, Lepidophthalmus and Neocallichirus, Memoirs of Museum Victoria (Mem. Mus. Vic.) 82, pp. 71-95 : 79-81

Mucrollichirus mucronatus ( Strahl, 1862)

Figure 6

Callianassa mucronata Strahl, 1862: 1056–1060 . — De Man, 1888: 484–485, pl. 21 fig. 2 (record from Ambon).— Poore and Griffin, 1979: 273–275, figs 34, 35.

Callianassa brevicaudata A. Milne-Edwards, 1870: 91–92 (type locality, Zanzibar [ Tanzania]).

Neocallichirus mucronatus .— Sakai, 1999: 105–107, fig. 26 (synonymy).— Sakai, 2011: 462–463 (full synonymy).— Sakai and Türkay, 2014: 185–187 (synonymy).— Dworschak, 2018: 31–36, figs 10, 11.

Callianassa (Cheramus) novaeguineae Thallwitz, 1891: 31–33 , pl. 3 fig. 9 (type locality, Nordwest Neu-Guinea ( Indonesia).

Callianassa novaeguineae .— De Man, 1902: 757–758.

Callianassa (Callichirus) mucronata . —De Man, 1928a: 175–179, pl. 19, figs 30–30e (record from Ambon).

Mucrollichirus mucronatus .— Poore et al., 2019: 144.— Robles et al., 2020: figs 1, 4, 7, tables S1, S2.

Material examined. Djibouti and Perim, coll. Dr Jousseaume, 1897, det. G. Nobili, AM P.5387 (2 females, 7.2, 8.6 mm) . Madagascar, Nosy Bé , lagoon S of CNRO, muddy coral, 13.416° S, 48.29044° E, 23–25 m, UF 13925 (female, 8.5 mm) . Papua New Guinea ( PAPUA NIUGINI stns). Madang Province. Sek I., 0–2 m, 05° 04.8' S, 145° 48.9' E (stn

PR26) MNHN IU-2013-558 (female, 5.6 mm) ; Rempi area , E of Dumduman I., 2–13 m, 05° 01.18' S, 145° 48.0'E (stn PR63) MNHN IU-2013-7099 (ovigerous female, 3.0 mm) . New Ireland. E side of Globig I., coral rubble with algae, sand, 3–5 m, 02° 38.8' S, 150° 44.2' E (stn KZ21 ), MNHN IU-2014-1067 (male, 4.0 mm) ; Cape Sueusat , coral drop off, 6–12 m, 02° 37' S, 150° 46.3' E (stn KZ06 ), MNHN IU-20142480 * (female, 5.0 mm) ; Kavieng Lagoon , Byron Channel, SE Patio I., rubble slope, 2–7 m, 02° 36.6' S, 150° 32.9' E (stn KB40), MNHN IU-2014- 2576 * (female, 9.8 mm) ; NW side of Ral I., 19 m, 02° 36.4' S, 150° 42.4' E (stn KB62), MNHN IU-2014-2776 * (lost) , MNHN IU-2014-2777 * (male, 2.5 mm) . Australia, Qld, Rat I, AM P.2010 (male, 8.0 mm); Palm I., AM P.5194 (female, 10.1 mm). WA, S end of Ashmore Reef, 12° 16.7385' S, 122° 59.088' E, WAM C54241 (2 females) .

Size. Cl. to 10.3 mm.

Distribution. Western and Central Indo-Pacific. The species has been widely reported from the Philippines (type locality: Luzon) ( Dworschak, 1992, 2018), Indonesia (De Man, 1928a), Papua New Guinea, Maldives ( Ortmann, 1894), north Queensland, Australia ( Poore and Griffin, 1979), Djibouti and Madagascar ( Sakai, 1999), and the Red Sea (Sakai et al., 2014). The identity of the specimens from Australia was confirmed as part of this study.

Remarks. Strahl (1862) reported on one female of C. mucronata of 13 lines (27.5 mm) without chelipeds from Luzon, Philippines, but supplemented his description with mention of a second smaller one of about 5 lines (10.6 mm). Tirmizi (1977) redescribed the larger one ( ZMB 1128) as the holotype without noting the presence of a second specimen; this is an effective lectotype designation ( ICZN Article 74.5). Sakai (1999) examined both specimens and alleged that Tirmizi’s fig. 1B of the front of the carapace, eyestalks and antennules and antennae was of the smaller specimen. As argued by Dworschak (2018), this is improbable. The scale bars provided by Tirmizi (1977) and by Sakai (1999) indicate that the front of the carapace is about 4 mm wide. Tirmizi’s fig. 1A of the dorsal habitus, fig. 1B of the front, and Sakai’s fig. 26a of the front are all from the lectotype (called holotype by both authors). Sakai (1999: 44–46, fig. 8) described the smaller specimen ( ZMB 27222) as Callianassa gruneri Sakai, 1999 . The figure suggests that the fragments came from more than one species, and Poore et al. (2019) listed C. gruneri as incerta sedis.

The syntypes of C. novaeguineae were collected in “Nordwest Neu-Guinea” (now West Papua Province or Papua Province, Indonesia) and comprise a fairly well-preserved specimen of total length c. 40 mm and broken pieces of a smaller one. They were lodged in MTKD but were probably destroyed during World War II. De Man (1902) redescribed the entire syntype and suspected the species to be synonymous with C. mucronata . He later treated them as synonyms and redescribed and reillustrated material from Ambon, Indonesia (De Man, 1928a), specimens that he had previously identified as C. mucronata (De Man, 1888) . Both names were included as synonyms and transferred to Neocallichirus by Sakai (1999) and later authors.

The male pleopods have not previously been illustrated, except for the tip of the endopod ( Sakai, 1999: fig. 26i). Sakai (1999) described pleopod 1 as of two articles, the second one “chelate”. In two small males from Papua New Guinea, pleopod 1 has two articles, the second article of one male with a deep apical longitudinal slit (fig. 6l, k). Pleopod 2 is biramous; an appendix interna is obvious in one small male (fig. 5j, l). The female pleopod 1 is of two articles (De Man, 1928a: pl. 19 fig. 30e; Tirmizi, 1977: fig. 3B; Dworschak, 2018: fig. 10c), typical of callichirids, not three as stated by Sakai (1999). The female pleopod 2 has a broad endopod with an obliquely truncate apex, with a small appendix interna (fig. 5n; see too Tirmizi, 1977: fig. 3C; Dworschak, 2018: fig. 10f, g).

Molecular data found no genetic divergence between Philippines and Papua New Guinea populations identifiable as M. mucronatus ( Robles et al., 2020) . Morphological differences are slight. De Man (1928a) noted that the posterior border of the uropodal endopod of his specimens from Ambon is regularly rounded (De Man, 1888: pl. 19 fig. 2a) while in the type of C. mucronata it appears obtusely angular in the middle. He believed that “this slight difference is no doubt individual”. Tirmizi’s (1977: fig. 1C) and Sakai’s (1999: fig. 26c) figures show this margin to be evenly curved, as in the new material from Papua New Guinea (fig. 5d). Another from Djibouti was found to have narrower uropodal rami than typical individuals (fig. 6a). Revival from synonymy of Callianassa novaeguineae cannot be justified.