Phanogenia Lovén, 1866

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 : 169-170

Phanogenia Lovén, 1866

Table 1, Fig. 7

Type species. Phanogenia typica Lovén, 1866 .

Other included taxa (7). Alecto Novae Guineae Müller, 1841 ; Actinometra distincta Carpenter, 1888 ; Actinometra gracilis Hartlaub, 1893 ; Actinometra multibrachiata Carpenter, 1888 ; Comaster fruticosus AH Clark, 1911b; Comaster schönovi AH Clark, 1918a; Comatula serrata AH Clark, 1907b; Comaster sibogae AH Clark, 1912a.

Diagnosis. Mouth central in fully developed individuals; up to 170 arms; cirri absent or present; IBr2 series united by cryptosynarthry or synarthry; first syzygy at 3+4 on arms arising from IBr, at 1+2 on arms arising from subsequent brachitaxes; IIBr and subsequent brachitaxes 2(1+2) or 4(3+4); distal intersyzygial interval 3–4; pinnule combs at intervals to near arm tip; comb teeth tall, triangular to spade-shaped, confluent with outer edge of pinnule; proximal tooth saucer-like and transverse.

Distribution. Tropical Indo-western Pacific from northern Australia (Jurien Bay, WA, to Lady Elliott I., QLD), west to Madagascar and the Red Sea, east to Fiji and Kwajalein Atoll, and north to Sagami Bay, Japan ( Chen et al. 1988; AH Clark 1931; AM Clark 1972; Kogo & Fujita 2014; Rowe & Gates 1995; Zmarzly 1985). Depth range: 0–210 m; only P. distincta and P. serrata occur regularly at depths greater than 100 m; a few records from greater depths are likely errors.

Molecular results. Molecular results for this genus are congruent with results in Owen et al. 2009 ( Fig. 7 ). Clade A of Owen et al. (2009) is herein referred to as Phanogenia typica based on a new specimen collected near the type locality, New Harbor , Singapore ; Clade B is designated as Phanogenia gracilis type A; and Clade C is designated Phanogenia gracilis type B. Phanogenia gracilis type A and type B had greater than 5.5% pairwise divergence in uncorrected COI (intra specific divergences of less than 2.5% for both). Both were at least 3.3% and 4.0% divergent relative to P. typica and P. multibrachiata , respectively . No morphological characters have been found that distinguish among P. gracilis type A, P. gracilis type B, and P. typica (e.g., Owen et al. 2009, and below). Also, current data does not allow determining to which clade the name gracilis should apply. The type locality for P. gracilis is Edam Island , Java Sea, Indonesia (Göttingen Museum), from which we lack specimens. Phanogenia typica alone returned up to 8.6% intra specific divergence, in comparison with only 0.5% for P. multibrachiata , suggesting that the former may include additional cryptic species.

Remarks. Three taxa in Phanogenia are reported as reef-dwellers: P. gracilis , P. typica , and P. multibrachiata ( Messing 1998a, and references therein). The first two have a reduced centrodorsal with at most a few rudimentary cirri in small specimens. The second has a well-developed centrodorsal with numerous cirri.

Messing (1998a) distinguished the holotype of P. typica , from Singapore, on the basis of its longer pinnule combs relative to those of P. gracilis from elsewhere, in specimens of similar size: 24–29 teeth on P1, and rarely fewer than 10 teeth on brachial pinnules, versus P1 with only 10–12 teeth and almost always fewer than 10 teeth on subsequent pinnules, respectively. He therefore treated all acirrate Phanogenia from Indo-western Pacific reefs except the P. typica holotype as P. gracilis sensu lato. However, new material from the Singapore type locality includes specimens with long “ P. typica ” combs as well as other specimens, otherwise indistinguishable (including the same color pattern) and from the same habitat, with short “ P. gracilis ” combs ( Messing & Tay 2016). Similarly, comb form varies among specimens in all three molecular clades discussed above. The P. typica clade was so named because it includes a long-combed specimen from the Singapore type locality.

The remaining taxa resemble P. multibrachiata in having a well-developed centrodorsal with numerous cirri. They differ chiefly on the basis of characters that vary with size, i.e., arm number and number and proportion of cirrals, with smaller taxa generally recorded from greater depths, e.g., P. multibrachiata (to 160 arms; ~ 20–50 m), P. fruticosa (37–63 arms; 35–106 m), P. sibogae (60 arms; 88 m), P. distincta (30–50 arms; 15–290 [chiefly ~70– 110] m), and P. serrata (13–30 arms; 100–174 m) (AH Clark 1931; AM Clark 1972; Kirkendale & Messing 2003; Kogo 1998; Messing, unpublished observations). Some or all may prove to be synonyms. Chen et al.’s (1988) report of a small P. distincta from reef crevices in 12–25 m off China may be a juvenile P. multibrachiata . Messing (1998) noted that the holotype of P. novaeguineae (60 arms; no depth recorded), currently treated as accepted (Messing 2001), appeared intermediate between P. fruticosa and P. multibrachiata and that the three might prove developmental stages of a single species.

Figures

FIGURE 7. Maximum likelihood tree of Phanogenia inferred from COI. Symbols and labels as in Figure 2. Location abbreviations—Borneo (Born); Great Barrier Reef, Australia (GBR); Malaysia (Malay); Papua New Guinea (PNG); Philippines (Philip); Raja Ampat, Indonesia (Raja); Singapore Strait, Singapore (Sing); Viligili, Maldives (Mald). New COI sequences are Genbank KR 010294 - KR 010306.