Caymanostella loresae Shen, Koch, Seid, Tilic & Rouse, 2024, sp. nov.
Creators: name: Shen, Zihui
name: Koch, Nicolás Mongiardino
name: Seid, Charlotte A.
name: Tilic, Ekin
name: Rouse, Greg W.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Echinodermata
Asteroidea
Velatida
Caymanostellidae
Caymanostella
Caymanostella loresae

description: Caymanostella loresae sp. nov.
Figures 14–16
Diagnosis. Body pentagonal or subpentagonal. Thick epidermis. Dense and granuliform abactinal armaments. Central disc plates circular, imbricating irregularly. Gonopores visible, piercing through the proximal-most superomarginal plates. Madreporite with branching grooves. One row of dorsal-lateral plates on each side of a row of carinal plates until arm tip. Terminal plate slightly trapezoidal. Inferomarginals more elongate than adjoining superomarginals. Short adambulacral spines covered with thick epidermis.
Materials examined. Holotype: ICML-EMU-13880 (formerly SIO-BIC E11477), on wood at Tamayo Fracture Zone, Gulf of California, Mexico, 22.9628 ° N, 108.1576 ° W, 3054 m depth, April 11, 2003, ROV Tiburon dive 553, collector Bob Vrijenhoek and party. Paratypes: SMF 6940 (prepared for µCT), E11393B (prepared for SEM), SIO-BIC E11393C, SIO-BIC E11393D, USNM 1487403 [GenBank COI= PP627129; 16S=PP572464; H3= PP658051], same collection data as holotype; USNM 1487403 was ethanol-fixed and the other five specimens were formalin-fixed.
Description. Adult body pentagonal to subpentagonal (R = 5.36–6.72 mm, r = 4.48–5.94 mm, R/r = 1.09–1.24; Holotype R = 6.47 mm, r = 5.86 mm, R/r =1.10, bent, measurement may not be accurate). Thick epidermis and dense armaments obscure plates.Abactinal side, excluding the inferomarginal plates, is slightly convex. Central disc plates differ from other abactinal plates in their mainly circular to subcircular shapes, imbricating irregularly. Other abactinal plates show regular distally imbricating patterns. Five primary inter-radial plates are irregular in shape and large. Madreporite has multiple branching grooves and is obscured by abactinal granules and epidermis (Figs 14E, 15B). Arms are wide, with oval to pentagonal abactinal plates more elongated relative to central disc plates. One row of distal-lateral plates on each side of the carinal plates that can be absent near arm tip (Fig. 16A). Terminal plate slightly trapezoidal, with distal end wider than proximal end (Fig. 16A).
Parallel rows of pentagonal superomarginal plates and inferomarginal plates along the body margin, imbricating radially, 9–10 plates each. Each inferomarginal plate is more elongated than the adjoining superomarginal plate (Figs 15B, C, 16A). The proximal-most superomarginal plates are oval-shaped and the largest, wider than long. One gonopore pierces through each of the proximal-most superomarginal plates (Figs 14A, C, E, 15B, 16B). All abactinal plates and abactinal side of marginal plates covered and obscured by dense small and round abactinal granules (0.06–0.1 mm, density>80/mm 2). Abactinal granules consist of a smooth short base and a spikey dome-shaped crown (Fig. 16E, F). Granules tend to be larger, more elongated and more cone-shaped around gonopores, terminal pores and near the distal edge of inferomarginal plates. Fringe spines (0.37–0.47 mm) club shaped from actinal/abactinal views and wing-shaped from lateral views. With many small pores and thorns, which are denser on the abactinal side (Fig. 16G, H). No obvious longitudinal ridges along the spines. Two fringe spines attach to the margin of each inferomarginal plate. There are 2–3 fringe spines at the margin of each terminal plate.
Ambulacral furrows slightly petaloid and each has 11–14 pairs of tube feet. Bar-shaped adambulacral plates (10–11 pairs in bleached paratype, Fig. 14D, F) obscured by adambulacral spines and epidermis. Adambulacral spines (0.4–0.69 mm) are tapering with wide base and are covered by thick epidermis (Fig. 16C, D, I, J). They orient towards the body margin, aligned with the adambulacral plates (Fig. 16C). Each adambulacral plate bears one furrow spine similar to adambulacral spines, but orient either perpendicular to the plates or pointing towards the furrow (Figs 14F, 15A). The oral side of inferomarginal plates have spines morphologically identical to adambulacral spines, also orienting towards body margin. Thick epidermis and dense spines obscure plate outlines. Paired oral plates are at the base of the interradius and form a ridge in-between. Each oral plate bears two suboral spines and 3 (sometimes 2) marginal oral spines pointing towards the interradius (Fig. 14B, F). In some cases, the number marginal oral spines on the paired oral plates differ, with one bearing 3 while the other bearing 2. Oral opening round and wide (~ 4 mm), and the stomach slightly everted in the holotype. Actinal chambers triangular to heart-shaped, each containing two clusters of gonads separated by an interradial septum (Fig. 14B, D, F).
Variation. All paratypes are fully mature and are morphologically similar. Gonopores and madreporites obscured by dense abactinal granules and only become visible after removing tissues and granules with bleach. Distribution. Known only from Tamayo Fracture Zone, Gulf of California (Mexico), at 3054 m.
Remarks. The pentagonal body shape of Caymanostella loresae sp. nov. differs from that of C. scrippscognaticausa sp. nov. and C. davidalani sp. nov. The shape and pattern of imbricating central disc plates also distinguishes C. loresae sp. nov. from other species in Caymanostella (Table 6). Terminal plates are more trapezoidal than those of C. scrippscognaticausa sp. nov. and C. davidalani sp. nov. (Fig. 16A). Inferomarginal plates are elongated, but not as much as those of Belyaevostella (Rowe 1989; Fujita et al. 1994). As in C. admiranda and C. phorcynis, the gonopores of C. loresae sp. nov. pierce through the proximal-most superomarginal plates (Table 6). Abactinal granules are like those of C. admiranda in having dome-shaped crowns, yet are also narrower, exhibit a more prominent base, and have thorns that are less sharp (Table 6; Dilman et al. 2022). Fringe spines of C. loresae sp. nov. are also most like those of C. admiranda, both exhibiting dense small pores and small thorns (Table 6). Because of the thick epidermis, the actinal side appears fleshier (Fig. 13B) and takes longer to dissolve in bleach compared to adult specimens of C. scrippscognaticausa sp. nov. and C. davidalani sp. nov. When bleached, the adambulacral spines appear less tapering and elongate than those in C. scrippscognaticausa sp. nov. and C. davidalani sp. nov. (Table 6). Future work is required to compare the thick epidermis of C. loresae sp. nov. to that of Belyaevostella and their phylogenetic relationship involving molecular data. Caymanostella loresae sp. nov. was recovered as the sister to a clade consisted of C. cf. spinimarginata, C. davidalani sp. nov., C. scrippscognaticausa sp. nov. and C. laguardai with high support (Fig. 3), with a minimum of 14.3% divergence from this sister clade in COI (Table 3, excluding C. laguardai, for which there is no COI data). The uncorrected 16S distance between C. loresae sp. nov. and C. laguardai was 14.6% (Table 4).
Etymology. Caymanostella loresae sp. nov. is named for Lores López Gómez in recognition of her unwavering commitment to advancing gender equality and her compassionate sense of justice.
description: Published as part of Shen, Zihui, Koch, Nicolás Mongiardino, Seid, Charlotte A., Tilic, Ekin & Rouse, Greg W., 2024, Three New Species of Deep-Sea Wood-Associated Sea Stars (Asteroidea: Caymanostellidae) from the Eastern Pacific, pp. 351-388 in Zootaxa 5536 (3) on pages 379-383, DOI: 10.11646/zootaxa.5536.3.1, http://zenodo.org/record/14239072