Pentamera paraibanensis, Prata, Jessica & Christoffersen, Martin L., 2016

Prata, Jessica & Christoffersen, Martin L., 2016, A new species of Pentamera Ayres, 1852 from the Brazilian coast (Holothuroidea, Dendrochirotida, Phyllophoridae), ZooKeys 634, pp. 1-14 : 3-8

Taxon classification Animalia Dendrochirotida Phyllophoridae

Pentamera paraibanensis sp. n. Figs 1, 2, 3

Type specimen.

Holotype, UFPB.ECH-2229, João Pessoa, Paraiba State, Brazil, 7°05'01"S; 34°47'56"W, 10 m, associated to rhodoliths, 9 March 2006.

Type locality.

João Pessoa, Paraiba State, Brazil, 7°05'01"S; 34°47'56"W, 10 m, associated with rhodoliths, 9 March 2006.

Other type material.

Paratype, UFPB.ECH-2230, João Pessoa, Paraiba State, Brazil, 7°05'01"S; 34°47'56"W, 6 March 2006; Paratype, UFPB.ECH-2061, João Pessoa, Paraiba State, Brazil, 7°03'48"S; 34°45'10"W, 15 m, 21 March 2006; Paratype, UFPB.ECH-2048, João Pessoa, Paraiba State, Brazil, 07°05'05"S; 34°44'21"W, 12 m, 24 June 2005; Paratype, UFPB.ECH-2058, João Pessoa, Paraiba State, Brazil, 7°07'00"S; 34°43'54"W, 14 March 2006; Paratype, UFPB.ECH-2089, João Pessoa, Paraiba State, Brazil, 7°03'50"S; 34°47'19"W, 10 m, 21 March 2006.

Additional material.

UFPB.ECH-2088, João Pessoa, Paraiba State, Brazil, 6°59'01"S; 34°47'23"W, 10 m, 6 spec., 7 March, 2006; UFPB.ECH-141, João Pessoa, Paraiba State, Brazil, 6°59'01"S; 34°47'23"W, 100 spec, 7 March 2006; UFPB.ECH-148, João Pessoa, Paraiba State, Brazil, 6°59'00"S; 34°46'41"W, 4 spec, 7 March 2006; UFPB.ECH-1684, João Pessoa, Paraiba State, Brazil, 6°59'01"S; 34°45'12"W, 20m, 1 spec., 7 March 2006; UFPB.ECH-145, João Pessoa, Paraiba State, Brazil, 7°01'02"S; 34°47'55"W, 86 spec, 6 March 2006; UFPB.ECH-149, João Pessoa, Paraiba State, Brazil, 7°01'00"S; 34°46'02"W, 2 spec., 6 March 2006; UFPB.ECH-140, João Pessoa, Paraiba State, Brazil, 7°03'50"S; 34°47'19"W, 165 spec., 21 March 2006; UFPB.ECH-143, João Pessoa, Paraiba State, Brazil, 7°03'50"S; 34°47'19"W, 400 spec., 7 March 2006; UFPB.ECH-150, João Pessoa, Paraiba State, Brazil, 7°03'48"S; 34°45'10"W, 31 spec., 21 March 2006; UFPB.ECH-153, João Pessoa, Paraiba State, Brazil, 7°03'49"S; 34°43'12"W, 31 spec., 21 March 2006; UFPB.ECH-204, João Pessoa, Paraiba State, Brazil, 7°04'24,4"S; 34°47'49"W, 6 m, 42 spec., June 2005; UFPB.ECH-858, João Pessoa, Paraiba State, Brazil, 7°7'25,2"S; 34°6'35,0"W, 23 spec.; UFPB.ECH-857, João Pessoa, Paraiba State, Brazil, 7°8'28,836"S; 34°46'34,118"W, João Pessoa, PB, Brazil, 1 spec., 4 October 2007; UFPB.ECH-2087, João Pessoa, Paraiba State, Brazil, 7°03'49"S; 34°47'19"W, 1 spec., 21 March 2006; UFPB.ECH-205, Picãozinho, North Point, João Pessoa, Paraiba State, Brazil, 1 spec., 12 June 2003; UFPB.ECH-2072, João Pessoa, Paraiba State, Brazil, 7°43'09"S; 34°45'00"W, 1 spec.; UFPB.ECH-2068, Coqueirinho Beach, Conde, Paraiba State, Brazil, 1 spec., 3 June 2008; UFPB.ECH-2059, João Pessoa, Paraiba State, Brazil, 07°07'00"S; 34°43'54"W, 1 spec., 11 March 2006; UFPB.ECH-2053, João Pessoa, Paraiba State, Brazil, 07°05'05"S; 34°44'21"W, 12m, 5 spec., 24 June 2005; UFPB.ECH-2057, Reefs in front of the yacht club, Bessa Beach, João Pessoa, Paraiba State, Brazil, 1 spec., 26 February 2006; UFPB.ECH-2049, João Pessoa, Paraiba State, Brazil, 7°05'01"S; 34°47'56"W, 50 spec., 9 March 2006; UFPB.ECH-2052, João Pessoa, Paraiba State, Brazil, 7°05'S, 10 m, 15 spec., 22 February 2006; UFPB.ECH-2037, Cabo Branco Beach, João Pessoa, Paraiba State, Brazil, 1 spec., 17 September 2001; UFPB.ECH-2038, João Pessoa, Paraiba State, Brazil, 7°03'48"S; 34°45'W, 15m, 5 spec., 21 March 2006; UFPB.ECH-2033, João Pessoa, Paraiba State, Brazil, 7°01'02"S; 34°47'55"W, 10m, 13 spec., 6 March 2006; UFPB.ECH-2030, João Pessoa, Paraiba State, Brazil, 7°05'01"S; 34°47'56" W, 93 spec., 9 March 2006; UFPB.ECH-2031, João Pessoa, Paraiba State, Brazil, 7°05'59"S; 34°46'04"W, 10 m, 226 spec., 14 March 2006; UFPB.ECH-1683, João Pessoa, Paraiba State, Brazil, 7°05'05.1"S; 34°44'21"W, 12 m, 14 spec., 24 June 2005.

Diagnosis.

Small body, reaching 7 mm, anterior and posterior ends slightly upturned. Color brown in life and in alcohol, tube feet light brown to white. Tube feet only in the radii. Tentacles ten, branched, two ventral ones smaller. Skin thin, smooth. Body wall ossicles comprise oval tables (with disc up to 64 µm long) with four central holes, sometimes more elongated and also with smaller holes marginally and smooth multilocular plates; spire low, with two short pillars ending in 2-3 blunt teeth. Tube feet with supporting plates, curved support tables of variable height, and endplates. Tentacles with rosettes and rods. Introvert with rosettes.

Etymology.

The species epithet is derived from the name of the State where it was collected ( Paraíba State, Brazil).

Description of holotype.

Specimen (female) small, globiform, slightly curved, length along the body 7 mm and breadth in mid-body 3 mm (Figure 1A, B, C). Preserved coloration brown, podia and tentacles light brown to white. Mouth upturned; anus terminal with five small papillae and five delicate anal teeth (Figure 3J). Tentacles extended, ten, well-branched, largest about 1.5-2 mm long, two ventral ones smaller. Tube feet restricted to radii, in double rows, longer in the ventral radii, shorter dorsally. Interambulacra usually naked, without papillae, warts or tubercles. Skin smooth, slightly translucid, with numerous small ossicles. Introvert thin, short, without tube feet.

Calcareous ring complex, not fragmented, with posterior processes elongated (Figure 1G). Radial plates longer than interradial, approximately 2 mm high and 0.5 mm wide, anterior part bifid, posterior processes with small pieces; interradial plates triangular anteriorly, with posterior margin convex, 1.3 mm high and 0.3 mm wide. Polian vesicle single, short, saccular, located slightly to left of ventral mesentery; stone canal thin, straight, elongated; madreporite well calcified, bean-shaped. Gonads in one tuft of several tubules attached anteriorly, unbranched but forming several saccules along the tubule, filling the entire body cavity, full of eggs in various stages of development. Longitudinal muscles thin; retractors also thin, more delicate. Respiratory trees confined to posterior quarter of body, with short branches.

Characteristic ossicles of body wall as oval tables with disc of usually four perforations and a low spire of two pillars (Figures 1I and 2D and H), 50-70 µm long and 20-30 µm high, ending in 2-3 teeth. Other body wall ossicles include some irregular smooth plates (Figure 3G). Tube feet ossicles of three types, supporting tables with curved disc with four central holes and 1-3 holes at ends, disc 128 µm long and spire 30 µm high (Figures 1J; 2 F–G, and 3 B–F). Elongate perforated plates, 99 µm long and 40 µm wide (Figure 2E and 3A), and rounded endplates with central perforations smaller than others, about 170 µm in diameter (Figure 3 H–I). Some large plates also occur near the podia (Figure 2I). Introvert with rosettes only (Figure 2C). Tentacles with rods of various sizes, some delicate, with perforations at each end, some curved, others with four arms; irregular perforated plates, oblong, straight to slightly curved, medial perforations larger (Figure 2B) and rosettes similar to those of introvert (Figure 1H, 2A).

Morphometry.

(See Table 1 below). Rosettes of tentacles are larger than those of introvert. In general, ossicles from dorsal surface larger than those from ventral surface. Dorsally, tables of anterior region are larger than of posterior region but their spire is lower. Endplates are also larger anteriorly. Supporting tables of the podia are smaller in posterior region, but are wider and higher anteriorly. On ventral surface, the tables from anterior part are slightly larger than posteriorly. Endplates of the postero-ventral surface are larger than the anterodorsal surface, about 140 µm in diameter. The supporting tables are slightly larger and taller anteriorly, but wider posteriorly (108.08 × 26.51 × 17.47 µm). The supporting plates from the posterior region are larger, approx. 103 µm.

Description of paratypes.

The paratypes are from 0.4 to 1 cm long. The ossicles of the body wall and other parts of the body are similar. Some tables are more elongated or have more than four perforations. The color varies from light to dark brown. Some specimens have their body dark brown and their tube feet light brown (Figures 1 D–F).

Color variations.

A total of 3225 specimens was examined, measuring 3-13 mm long and 3-3.5 mm wide in the mid part, and 1-2.5 mm at the ends were examined. In general, they all present a curved form, but some specimens are elongated or only slightly curved. The body wall is dark to light brown in color, sometimes with dark spots, the tube feet varying from whitish to yellowish, and the tentacles with translucent peduncles and brown to yellow branches. Most specimens present a brown coloration, with some dark brown spots and whitish tube feet.

Distribution.

Bessa beach, reefs of Picãozinho, Cabo Branco beach, in Municipality of João Pessoa; Coqueirinho Beach, in municipality of Conde; with coordinates 6°59'01"S; 34°45'12"W and 7°43'09"S; 34°47'56"W, coast of Paraíba State, Brazil. Species found over the continental platform of the State of Paraíba, Brazil, up to 20 m deep.

Habitat.

Most specimens were inside rhodoliths, but some samples were associated with Halimeda sp., were part of the phytal of Hypneia sp., or came from a rocky bottom.

Remarks.

The new species seems to shed the calcareous ring when submitted to stress. Some specimens were without the tentacles and calcareous ring, and most of them presented tentacles and the calcareous ring totally extended outside the body. This seems a defense tactic of this animal. The specimens studied agree with the diagnosis of genus Pentamera as amended by Lambert (1998). They share the structure of the calcareous ring and the type of body wall ossicles with other species currently classified in the genus Pentamera . Pentamera paraibanensis sp. n. with its double row of tube feet, body wall with tables with two pillars, and with the shape of the supporting tables and endplates, has parallels with other species of the genus. Pentamera paraibanensis sp. n. has similar tables as those of Pentamera pediparva and Pentamera constricta , but differs from both in the moderate calcareous ring, height of spire of supporting tables of tube feet, presence of rods and rosettes in tentacles and only rosettes in the introvert. In addition, these species have stiff and rough skin, while Pentamera paraibanensis sp. n. has soft and smooth skin. We also compared the new species with other species of the genus Pentamera , as well as with other species of Phyllophoridae reported from the South Atlantic directly or through specialized literature (e.g., Cherbonnier (1951), Deichmann (1930, 1938, 1941), Lambert (1998), and Tommasi (1969).

The new species Pentamera paraibanensis sp. n. differs of Pentamera beebei Deichmann, 1938 and Pentamera zacae Deichmann, 1938 by the absence of high pillars of the body wall tables; from Pentamera chierchiae (Ludwig, 1887) by the absence of rods in the introvert and tables with spinous disc; from Pentamera chiloensis (Ludwig, 1887) by the absence of quadrangular base of tables from the body wall, with pillars ending in several teeth; from Pentamera calcigera Stimpson, 1851 it can be distinguished by the absence of a dense layer of plates and by the form of the tables from the body wall; from Pentamera charlottae Deichmann, 1938 by the absence of small tables from the body wall; from Pentamera lissoplaca (Clark, 1924) by the absence of diamond-shaped tables and diminutive tables in the body wall. Pentamera paraibanensis sp. n. differs from Pentamera trachyplaca (Clark, 1924) by the absence of thick oval knobbed plates; from Pentamera pseudocalcigera Deichmann, 1938 by the absence of star-shaped plates in the body wall; and from Pentamera rigida Lambert, 1998 it may be clearly distinguished by absence of large thick tables, knobbed plates in introvert and the shape of the calcareous ring.

Pentamera paraibanensis sp. n. distinguishes of the other Phyllophoridae species recorded to South Atlantic, Euthyonidiella occidentalis (Ludwig, 1875), Neothyonidium parvum (Ludwig, 1881), Stolus cognatus (Lampert, 1885), Thyone pawsoni Tommasi, 1972 and Thyone pseudofusus Deichmann, 1930 by the form of the calcareous ring, arrangement of the tube feet on the body, and set of ossicles from body wall.