Lipotrapeza purpurata

Yamana, Yusuke & Kohtsuka, Hisanori, 2018, Dendrochirotid holothurians (Echinodermata: Holothuroidea: Dendrochirotida) including four new species, from off Misaki, Japan, Zootaxa 4455 (3), pp. 429-453: 440-445

publication ID

https://doi.org/10.11646/zootaxa.4455.3.2

publication LSID

lsid:zoobank.org:pub:A01F20BE-F0C4-4B45-97C5-E996A2C84EE1

persistent identifier

http://treatment.plazi.org/id/6D72879E-FFAB-0C60-D7A2-F906E3FB8CF0

treatment provided by

Plazi

scientific name

Lipotrapeza purpurata
status

sp. nov.

Lipotrapeza purpurata  sp. nov.

[New Japanese name: Murasaki-honenashi-namako]

( Figs 1E View Figure , 2E View Figure , 7A–P View Figure )

Material examined. Holotype, WMNH-INV- 2015-39 (St. 1, 26 August 2014, length 21 mm, width 5 mm). Paratypes: WMNH-INV- 2015-38 (St. 1, 26 August 2014, length 28 mm, width 9 mm, partially eviscerated); WMNH-INV- 2015-40 (St. 1, 26 August 2014, length 32 mm, width 11 mm, extremely expanded); WMNH-INV- 2016-4 (St. 1, 26 August 2014, length 8 mm, width 3 mm, partially eviscerated).

Other material: 1 specimen, WMNH-INV-2015-8 (St. 1, 26 August 2014, length 9 mm, width 3 mm, eviscerating); 1 specimen, WMNH-INV- 2015-37 (St. 1, 26 August 2014, length 13 mm, width 6 mm); 1 specimen, WMNH-INV- 2015-41 (St. 1, 26 August 2014, length 21 mm, width 6 mm, partially eviscerated); 1 specimen, WMNH-INV- 2017-41 (St. 1, 26 August 2014, length 13 mm, width 6 mm).

Description of holotype. Body fusiform, straight or curved, with both ends tapered and turned slightly upwards ( Fig. 1E View Figure ); body wall thick and soft. Body color dark purplish brown or brownish white (living and preserved specimens), inside of body cavity purplish white and inside of pedicel dark purple (preserved specimens). Tentacles 20, arranged in double circle (15 + 5), including five pairs of large inter radial tentacles and five single small radial tentacles in outer circle and five small radial tentacles in inner circle. Color of tentacles and introvert, cream or whitish-brown (living and preserved material). Several rows of villi-like projections surrounding oral opening, short and wide, dark purplish brown (living and preserving). Pedicels non-retractile or partially retractile, scattered over entire body, lacking on introvert, becoming gradually smaller anteriorly and posteriorly. Color of pedicels same as body wall, occasionally tips tinged with dark purplish color. Ten anal papillae and five anal teeth in radii.

Calcareous ring long ( Fig. 2E View Figure ), radial and most of interradial elements not fragmented. Radials entire, anteriorly notched, carrying paired, fragmented, posterior prolongations. Interradials plates sagittate, sharply pointed anteriorly, divided into two fragments, lacking posterior prolongations. Polian vesicle and stone canal single. Gonad situated in mid-body, in two clusters, one on each side of dorsal mesentery, most tubules unbranched.

The holotype possesses rosettes in the body wall ( Fig. 7F, G View Figure , Table 5), typical of the open type, branches rarely overlapping. Anal papilla with rosettes, rods, tables, and plates ( Fig. 7H View Figure , Table 5). Tentacle ossicles comprise rods and rosettes ( Fig. 7A View Figure , Table 5); rods, short, simple, with small numbers of distal branches and a few distal perforations. Peri-oral skin, pharyngeal villi and introvert with rosettes ( Fig. 7B–D View Figure , Table 5). Pedicels with circular endplate and other supporting plates ( Fig. 7E View Figure , Table 5). Endplate with approximately uniform-sized perforations; perforations of supporting plates mostly arranged in single or double rows medially and three or more rows distally. Anal papillae with mostly simple rods distally, other rods present in middle to basal part, and simple-shaped tables and rosettes present only in basal part of anal papilla and anal periphery. Most tables with low spire with four pillars and eight teeth, disc with 8-10 marginal perforations. Gonad lacking ossicles.

Description of paratypes. Body color varies among specimens from purplish to light brown; some swollen specimens with thin transparent purplish skin ( Fig. 1E View Figure ). Color of body cavity, oral opening, and inside of body and pedicel wall are uniform. In small specimens, large pedicels form two longitudinal rows along each radius, and small pedicels sparsley distributed in the interradii.

In a swollen, immature paratype (WMNH-INV- 2015-40), tentacle with swollen rods ( Fig. 7I View Figure ), and without the usual rosettes. Peri-oral skin and pharyngeal villi with the usual rosettes ( Fig. 7J, K View Figure ), similar to those of holotype. Introvert with usual rosettes and additionally with table-like ossicles and large, rosette-derived plates ( Fig. 7L View Figure ). Pedicel with normal endplate and supporting plates ( Fig. 7M View Figure ), similar to those of holotype. Mid-body wall lacking rosettes but tables present ( Fig. 7N, O View Figure ). Ossicles of anal papilla exhibit rosettes, rods, tables, and supporting tables ( Fig. 7P View Figure ), as in holotype.

Remarks. This species has 20 tentacles, a peculiar calcareous ring, and rosette ossicles in the introvert and body wall. This combination of features is typical of the genus Lipotrapeza  . Among the Lipotrapeza  , a long calcareous ring had been only observed in two nominal species, L. japonica Heding & Panning, 1954  , and L. littoralis Yamana & Kohtsuka, 2017  . However, the number of anal papillae of the present species is significantly different from L. japonica  , in which only five papillae are present ( Heding & Panning 1954; Yamana & Kohtsuka 2017). The present species is also distinguishable from both L. japonica  and L. littoralis  , by the existence of rosette ossicles and/or tables in the body wall, while no ossicles are present in the body wall of L. japonica  and L. littoralis  ( Heding & Panning 1954; Yamana & Kohtsuka 2017).

Distribution. So far known only from the type locality, off Jyogashima Island, south coast of Kanagawa Prefecture, sand bottom, 87–88 m, Pacific Ocean, middle Japan.

Etymology. The specific name purpurata  alludes to its purplish color.