Neoferdina insolita Livingstone 1936

Mah, Christopher L., 2017, Overview of the Ferdina - like Goniasteridae (Echinodermata: Asteroidea) including a new subfamily, three new genera and fourteen new species, Zootaxa 4271 (1), pp. 1-72 : 50-53

Neoferdina insolita Livingstone 1936

Figure 17 A–F

Livingstone 1936: 384; Clark & Rowe 1971: 65 (in key); Rowe & Gates 1995: 89; Gosliner et al. 1996: 261; Coleman 2007: 41; Humann and deLoach 2010: 438; Antokhina & Britayev 2012: 899, 900 (Pl. 7, fig. 29). (as Neoferdina insolita )

Occurrence. Sagami Sea, central Japan (see below), Papua New Guinea, Australia (west coast of Great Barrier Reef), Taiwan (Gulf of Tonkin), 3– 80 m .

Comments. Although very little has been published on this species since its description, there is a growing body of evidence that suggests that individuals which are identified as N. insolita (i.e., no abactinal bare regions, complete granular tegument on abactinal surface) includes a wide range of variation in morphology and color which could possibly reflect a cryptic species complex similar to the one perceived in N. cumingi and/or N. offreti . Diversity within the traditional N. insolita concept is presented below.

Two specimens from the Philippines were examined ( Fig. 17 A–F figures one specimen). These individuals were larger than the holotype (R=2.0 cm) and showed significant deviations from the specimen described by Livingstone (1936) but remained within the N. insolita concept, displaying no convex, bald abactinal plates in conjunction with showing large bald patches on the superomarginals ( Figs 17 B,C, C). The holotype shows elongate to oblong shaped carinal plates, whereas the three examined all show hexagonal to round/polygonal carinal plates ( Fig. 17 A, B, D). The two Balut Island specimens also have spines present on inferomarginal plates adjacent to the terminal.

Observations of living individuals consistent with Livingstone’s description in field guides, including Gosliner et al. (1996), Coleman (2007), Humann and deLoach (2010) and Kuiter and Debelius (2009). These all showed individuals with a flat abactinal surface with no convex, bare plates present but there was significant variation in color and plate patterns. Many of these images were not collected and so, specimen data documenting further morphological variation remains elusive.

At least three N. insolita color morphotypes have been observed. Gosliner et al. (1996) identified N. insolita with dark purple colored disk and white to light colored arm and dark, brick colored bare regions on the superomarginals from New South Wales, Australia which closely resembled the holotype described by Livingstone (1936). Three images presented by Coleman (2007: 41) also show images of N. insolita with this color pattern, imaged from Australia and Papua New Guinea, that also closely agree with the image of Livingstone’s (1936) holotype. Further complicating this morphotype is the apparent presence of convex bald regions similar to those on the superomarginals on one individual of the N. insolita figured by Coleman (2007: 41, the 50 mm specimen) but not on the other two with the identical color pattern, suggesting that in some cases this character varies between differently sized individuals.

A second morphotype, observed in Bali by Coleman (2007: 41), displayed a variably red and orange colored arm and disk as well as white arm tips. These were incorrectly identified as “ Neoferdina offreti .” This same redorange morphotype was also documented by Humann and deLoach (2010: 438). Kuiter and Debelius (2009: 577) identified two further individuals of the “red-orange” morphotype, also from Bali which also displayed this plate pattern and color pattern. Coleman (2007: 41) displayed further images of a species identified as “ Neoferdina offreti ” which displayed a plate pattern identical to the “red-orange” morphotype but was instead pink with a dark yellow disk with dark magenta patches on the superomarginals. A third color variant displaying similar plate patterns but showing purple color on the abactinal and marginal plates with yellow highlights has also been observed in Indonesia (P. Thorden, pers. comm).

A further consideration regarding this species also concerns the relatively small size of the holotype. Livingstone (1936) outlined concerns that this species was based on a juvenile specimen given the relatively small size of the holotype (R=2.0 cm), a concern later echoed by Jangoux (1973). Since the assessment of juvenile status was not based on gonad maturity or some other direct reproductive criteria, “juvenile” versus “adult” classifications appear to have been subjectively based on size. As more specimens of Neoferdina spp. have become available, further examined individual specimens of Neoferdina spp. have been shown to display a range between R=2.0 and 4.0 cm with unusually small specimens displaying R<1.5 cm.

Subsequent collections of specimens identified as Neoferdina insolita from the Australian Museum collections include smaller individuals comparable in size to the holotype as well as significantly larger individuals displaying easily twice the disk to arm length (R)l these larger individuals show minor morphological variation. It is unclear if the relatively small size of this and other individuals of N. insolita were “juvenile” or simply reflect a relatively small adult size.

The Neoferdina insolita cited by Chao (1999) from Taiwan is misidentified and is correctly identified as N. offreti , owing to its serial superomarginals and the presence of bare convex plates on the abactinal surface.

Material examined. CASIZ 218859 Balut Island , Philippines, no depth. 1 dry spec. 42989, R=2.9 r=0.8 ; CASIZ 218866 Camiguin Island, Philippines, Coll. trawl net. ~ 80 m 1 dry spec. R=2.3 r=0.4 ; CASIZ XX 28-1 Balut Island , Philippines, 150–200 m, Coll. tangle net. 1dry spec. R=1.5 r=0.4.

Figures

FIGURE 17. Neoferdina insolita. CASIZ 218859 Scale Bar = 3.5 mm. A. Abactinal surface. B. Detail of arms and disk. C. Detail showing superomarginals and disk contact. D. Abactinal surface showing arm detail, especially superomarginals E. Actinal surface. F. Detail on inferomarginal series, actinal surface.