Choneplax indica Odhner, 1919

Schwabe, Enrico, 2004, The Polyplacophora (Mollusca) collected during the First International Marine Biodiversity Workshop for Rodrigues (western Indian Ocean), with the description of a new species, Journal of Natural History 38 (23), pp. 3143-3173: 3160-3163

publication ID

http://doi.org/ 10.1080/00222930410001695114

persistent identifier

http://treatment.plazi.org/id/03B187BA-FFA3-D629-FE1F-FBD147ABF9F6

treatment provided by

Felipe

scientific name

Choneplax indica Odhner, 1919
status

 

Choneplax indica Odhner, 1919  

( figures 11–13 View FIG View FIG View FIG , 17D View FIG ) Choneplax indicus Odhner, 1919: 40   ; pl. 3, figures 44, 45; Ashby, 1928: 92; 1931: 53;

Bergenhayn, 1931: 3, pl. 1, figures 5–9 View FIG View FIG View FIG View FIG View FIG ; Winckworth, 1933: 319; Kaas and Van

Belle, 1980: 63; 1998: 95; Leloup, 1981a: 19; Kaas, 1985a: 331, 339; 1986: 20,

figures 62–72; Slieker, 2000: 50, pl. 13, figure 32; Sirenko, 2003: 33, 35, figure 1I View FIG .

Type. Holotype ( SMNH 1324 View Materials , indicated as syntype).  

Type locality. Tamatave , Madagascar   .

Material examined. 7 spms, 3.2 6 1.8 mm, ca 9.9 6 2.5 mm (curled) (pd), 3 6 1.2 mm, 2.7 6 1.2 mm, 4.7 6 1.9 mm, ca 5.7 6 1.9 mm (curled), ca 6 6 1.7 mm (curled): RDS 35, Grande Baie, 21.5 m, leg. N. Bruce; 3 spms, 5.7 6 1.6 mm, 5.9 6 1.8 mm, ca 6.3 6 2.1 mm (curled): RDS 32, Grand Pate´, 17.5 m, leg. N. Bruce; 1 spm, ca 10.3 6 3.3 mm (curled): RDS 31, Grand Pate´, 13–15 m, leg. N. Bruce.

Description

Animal elongate and nearly worm-like ( figure 17D View FIG ). Tegmentum finely granulated all over, except for smooth jugal area ( figure 11A–D View FIG ). The perinotum is densely covered with fine spicules and large tufts of longer needles.

Tegmentum. Head valve with very large, all-over granulated tegmentum. Granules arranged in quincunx ( figure 11A View FIG ). In intermediate valves granules arranged in longitudinal lines in pleurolateral areas and end without overlapping along the smooth (sculptured by numerous fine pores), wedge-shaped jugum ( figure 11B, C View FIG ). Mucro of tail valve is situated terminally, not elevated and inconspicuous ( figure 11D View FIG ). Postmucronal area lacking and ‘antemucronal area’ sculptured like intermediate valves, but the jugum is less wedge-shaped. Macroaesthetes of granules are situated posteriorly and surrounded by five microaesthetes ( figure 11C View FIG ).

Articulamentum. White, very thin and fragile. Slit formula: 3/0/0, slits in head valve very short. Slit rays visible in head valve only. Apophyses of intermediate valves rather large and triangular, and directed laterally, those of tail valve much shorter and closer to each other.

Perinotum. Rather wide, dorsally densely covered with small (62–72.5 6 13.8–15 M m), elongate, longitudinally ribbed spicules ( figure 12A, B, E View FIG ). Among them, larger (154.6–245.5 6 16.4–20 M m), flat, straight and longitudinally ribbed spicules may be found (often arranged in groups) ( figure 12A, B View FIG ). They are longer than the needles, which are arranged in the 18–20 tufts in groups of about 15 per tuft, which measure 163.6–216.7 6 36.4–43.6 M m ( figure 12A View FIG ). Along the margin, there are short spicules (40.9 6 10.2 M m), which are distinctly ribbed in their upper part ( figure 13B View FIG ). Ventrally, the girdle shows long, sharp-pointed, flat, smooth scales, 44.6–58.2 6 7.8 M m in size ( figure 13C, D View FIG ).

Radula. The disarticulated specimen has 38 rows of teeth, of which 27 are mineralized. Central tooth very short and stout, with a single, forward-projected blade and a transversal slit above the sharp-keeled shaft. First lateral tooth large and covers nearly completely the central one. Posteriorly it extends sidewards, whereas it is upward directed in the anterior portion ( figure 11E, F View FIG ). Major lateral tooth has a long shaft that is deeply grooved laterally. Head of the major lateral tooth tricuspid, with the denticles of nearly the same size. It is supported

by a slender, long spatulate uncinal tooth, which has a spoon-like, forwarddirected blade ( figure 11E View FIG ).

Ctenidia   . The wet preserved holotype (flattened, valves I, VzVIII missing; 9.7 6 2.7 mm) has 11 merobranchial and abanal ctenidia on the right side. Those from left side are inchoate.