Comanthus

Summers, Mindi M., Messing, Charles G. & Rouse, Greg W., 2017, The genera and species of Comatulidae (Comatulida: Crinoidea): taxonomic revisions and a molecular and morphological guide, Zootaxa 4268 (2), pp. 151-190 : 181-184

Comanthus AH Clark, 1908d

Table 1; Figs. 15–16

Type species. Alecto parvicirrus Müller, 1841 .

Other included taxa (9). Alecto wahlbergii Müller, 1843 ; Antedon briareus Bell, 1882 ; Comantheria weberi AH Clark, 1912a; Comanthus gisleni Rowe, Hoggett, Birtles & Vail, 1986 ; Comanthus kumi Fujita & Obuchi, 2012 ; Comanthus suavia Rowe, Hoggett, Birtles & Vail, 1986 ; Comaster imbricatus AH Clark, 1908e; Comaster taviana AH Clark, 1911e; Phanogenia delicata AH Clark, 1909f.

Diagnosis. Mouth excentric in fully developed individuals; up to 75 arms; centrodorsal circular to pentagonal; cirri present in one row or absent ( Fig. 15 B, D–F, H–I, K–L); IBr2 united by synarthry; IIBr and subsequent brachitaxes 2 or 4(3+4); first syzygy at 3+4 on all undivided arms; distal intersyzygial interval 4; distalmost pinnule comb at intervals sometimes reaching near arm tip; comb terminating in large discrete tooth; proximal tooth transverse, saucer-like ( Fig. 15 C); primary comb teeth confluent with exterior edge of pinnulars ( Fig. 15 C); smaller secondary tooth present or not.

Distribution. Indo-western Pacific from northern Australia (Perth, WA, to Julian Rocks, NSW) west to the Red Sea and eastern Africa as far south as Cape of Good Hope, east to Kwajalein Atoll and Vanuatu, and north to Chiba Peninsula, Japan, and possibly the Korean Straits (AH Clark 1931; Kogo 1998; Rowe & Gates 1995; Zmarzly 1984). Depth range: 0–120 m (chiefly <50 m).

Molecular results. The sequenced specimens identified as Comanthus were recovered in multiple clades, with varying support ( Fig. 16 ). All clades named in Fig. 16 were assignable based on morphology and were recovered with interspecific uncorrected COI distances of at least 5%, with the following exceptions: 1) Comanthus sp. 5 and Comanthus gisleni (3.4–4.3%); 2) Comanthus cf. suavia and Comanthus parvicirrus (3.8–5.3%); 3) Comanthus sp. 2 and Comanthus sp. 3 (4.7%); 4) Comanthus sp. 5 and Comanthus sp. 2 (~4%); and 5) Comanthus sp. 4 and Comanthus briareus (4.1%). Intra specific distances (where available) were less than 1.3%, with the exception of Comanthus parvicirrus (<2.7%) and Comanthus wahlbergii (<3.4%). Five clades interspersed among those that could be named ( Fig. 16 ) are arguably species-level taxa but were left unnamed owing to the dozens of available names that are currently treated as synonyms for C. wahlbergii and C. parvicirrus (e.g., AH Clark 1931; Rowe et al. 1986).

Remarks. It is not surprising that additional taxa likely exist within Comanthus , as the majority of current nominal species are widely distributed, include numerous synonyms, and some include different, probably habitatrelated, forms (e.g., Comanthus parvicirrus , Comanthus wahlbergii ). Distinguishing species of Comanthus remains difficult, as clear molecular boundaries for ‘species’ assignments are unclear.

SUBFAMILIAL ASSIGNMENT UNCERTAIN

Figures

FIGURE 15. Comanthus. (A – C) Comanthus parvicirrus— (A) live, with centrodorsal concealed within reef infrastructure; (B) aboral view showing centrodorsal with one row of cirri; (C) curled comb pinnule with transverse proximal comb tooth and triangular teeth confluent with exterior of pinnule. (D) Comanthus wahlbergii, aboral view showing centrodorsal with complete row of cirri. (E) Comanthus gisleni, aboral view showing centrodorsal with one row of cirri. (F) Comanthus suavia, aboral view showing centrodorsal without cirri. (G – H) Comanthus sp. 4 — (G) live, exposed on reef following extraction from coral rubble; (H) aboral view showing bright yellow centrodorsal with one row of cirri. (I) Comanthus sp. 2, aboral view. (J – K) Comanthus sp. 4, small specimen, oral (J) and aboral view (K). (L) Comanthus sp. 2, aboral view. Madang, Papua New Guinea: A. MNHN- IE- 2013 - 8117; G – H. MNHN-IE- 2013 - 8044; I. MNHN-IE- 2013 - 8034; J – K. MNHN-IE- 2013 - 8043; L. MNHN-IE- 2013 - 8037. Lizard Island, Australia: B – C. AM J 17388, neotype. Low Island, Queensland, Australia: E. AM J 13304, holotype. Between Palfrey and Lizard Island, Australia: F. AM J 17275, holotype. Raja Ampat, Indonesia: D. SIO-BIC E 6251.

FIGURE 16. Maximum likelihood tree of Comanthus inferred from COI. Symbols, labels, and location abbreviations as in Table 2. New COI sequences are Genbank KR 010245 - KR 010270.