Thouarella coronata Kinoshita, 1908

TAYLOR, M. L., CAIRNS, S. D., AGNEW, D. J. & ROGERS, A. D., 2013, <strong> A revision of the genus <em> Thouarella </ em> Gray, 1870 (Octocorallia: Primnoidae), including an illustrated dichotomous key, a new species description, and comments on <em> Plumarella </ em> Gray, 1870 and <em> Dasystenella </ em>, Versluys, 1906 </ strong>, Zootaxa 3602 (1), pp. 1-105 : 86-89

publication ID

https://doi.org/ 10.11646/zootaxa.3602.1.1

publication LSID

lsid:zoobank.org:pub:10304FBF-3969-4EFA-83F1-BB8A5E2B37F3

persistent identifier

https://treatment.plazi.org/id/EE36E867-FFD0-FFB3-FF0A-ABE5FAE10C71

treatment provided by

Felipe

scientific name

Thouarella coronata Kinoshita, 1908
status

 

22. Thouarella coronata Kinoshita, 1908 View in CoL

Figs 34 View FIGURE 34 , 35 View FIGURE 35

Thouarella (Diplocalyptra) coronata Kinoshita, 1908c: 519–520 View in CoL , fig. 2; 1908b: 56–59, figs 4–6 (in text); Cairns & Bayer 2009: 28 (list), 35, figs 7a–g

Thouarella coronata Aurivillius 1931: 255 View in CoL (listed)

Thouarella (Euthouarella) coronata Kükenthal 1915: 150 View in CoL (key); 1924: 296 (key)

Material examined: USNM 50118, fragment of holotype, UMUT, Uji Island , Kyushu Island, 146 m, May 1908, 13 cm colony of which we viewed 20 mm. A small fragment of the holotype was available for study, however, the colony shape and branchlet arrangement narrative below relies heavily on the original description .

Description

The colony is mostly sympodially branched with dichotomous branching in one upper portion of the colony (top left of Fig. 34a View FIGURE 34 ). Basal branchlets are up to 50 mm long, 5–12 mm apart, and on rare occasions 20 mm apart. The axis is brown with a yellowish metallic lustre.

The polyps are distally flared with a slender polyp body ( Fig. 34d,e View FIGURE 34 ) 1.9–2.1 mm high, standing perpendicular to the branchlet in pairs and sometimes whorls of 3 ( Fig. 34c View FIGURE 34 ), with 5–7 pairs or whorls per cm. There are 8 marginals, but only 7 longitudinal rows of body-wall scales with 5–6 scales in the abaxial rows.

The operculars are lanceolate to triangular in shape ( Fig. 35d–h View FIGURE 35 ), 260–455 µm high (average 290 µm), 120–240 µm wide (average 180 µm), with an average H:W of 1.6 (range from 1.3–2). The outer surface is smooth whilst the inner surface has a small elliptical tuberclulate area proximally and a smooth distal area.

Beneath the operculars are 3–4 (perhaps more in other samples) small accessory operculars ( Fig. 35a–c View FIGURE 35 ) which are irregular or tear-shaped, 80–200 µm high (average 150 µm), 70–140 µm wide (average 100 µm), with an average H:W of 1.1. The outer surface is smooth, the inner surface is also smooth with a small patch of tubercles proximally. The scale edges are relatively smooth (not serrated).

The marginals are equilateral triangle-shaped with a rounded proximal edge ( Fig. 35i–k View FIGURE 35 ), 430–560 µm high (average 490 µm), 270–330 µm wide (average 310 µm), with an average H:W of 1.6 (range from 1.3–2.1). The outer scale surface is smooth distally with granules proximally. The inner surface has a multi-channelled keel with smooth areas lateral to the keel and tubercles covering the proximal half below the keel base. A marginal scale’s proximal edge is roughly lobate, and may be angular.

Some submarginals have small keels or ridges on the distal edge of the inner surface and are a wide tear-shape and pointed distally ( Fig. 35l,m View FIGURE 35 ). They have a tuberculate inner surface with a narrow smooth band along the distal edge whilst the outer surface is smooth with some granules proximally.

Body-wall scales are circular ( Fig. 35n–p View FIGURE 35 ), 190–340 µm high (average 250 µm), 200–310 µm wide (average 240 µm), with an average H:W of 1.1 (range from 0.9–1.2). The outer surface is smooth, sometimes with granules proximally whilst the inner surface is tuberculate with a smooth band along the distal edge and infrequent small ridges running perpendicular to the edge. The distal edge of all polyp sclerites of this species is finely serrate (unless otherwise stated) whilst the proximal edge is coarsely lobate.

The coenenchymal scales are circular ( Fig. 35q View FIGURE 35 ), around 130 µm diameter and much smaller than the bodywall scales. The outer scale surface is smooth and slightly concave with edges raised from the axis whilst the inner surface is tuberculate.

Several hundred cylindrical rodlets were found in each tentacle.

Distribution

Known only from type locality, Kyushu Island , Japan, 146 m depth .

Remarks

This is the only Thouarella species known to contain tentacular rodlets, a form of sclerite often found in Plumarella . It is also the only Thouarella species known to have a sympodial branching pattern.

Comparisons

Although the majority of the T. coronata colony is sympodially branched a portion is dichotomously branched (more examples of this species are required to confirm the branching pattern). Apart from T. coronata , only two other species within Group 2 have dichotomous, uniplanar branching: T. parva , also from Japan, and T. biserialis ( Nutting, 1908) , from Hawai’i. Kinoshita’s drawings (1908d, figs 1, 2) indicate that T. parva differs from T. coronata in having shorter, more rounded marginals and polyps diverging from branchlets at approximately 45˚ rather than 90˚.

The sclerites of polyps of T. biserialis and T. coronata are very similar. The marginals of polyps of T. biserialis appear to curve over the operculum creating a cylindrical, rounded polyp, whereas those of T. coronata are flared outward. The polyps of the former are inclined at 45˚ and of the latter are perpendicular to branchlets. The importance of these characters remains unclear, so for now these species are considered to be distinct.

UMUT

University Museum, University of Tokyo

Kingdom

Animalia

Phylum

Cnidaria

Class

Anthozoa

Order

Alcyonacea

Family

Primnoidae

Genus

Thouarella

Loc

Thouarella coronata Kinoshita, 1908

TAYLOR, M. L., CAIRNS, S. D., AGNEW, D. J. & ROGERS, A. D. 2013
2013
Loc

Thouarella coronata

Aurivillius, M. 1931: 255
1931
Loc

Thouarella (Euthouarella) coronata Kükenthal 1915: 150

Kukenthal, W. 1915: 150
1915
Loc

Thouarella (Diplocalyptra) coronata

Cairns, S. D. & Bayer, F. M. 2009: 28
Kinoshita, K. 1908: 520
1908
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