Metapeachia schlenzae, Gusmão, Luciana C., 2016

Gusmão, Luciana C., 2016, Metapeachia schlenzae sp. nov. (Cnidaria: Actiniaria: Haloclavidae) a new burrowing sea anemone from Brazil, with a discussion of the genus Metapeachia, Zootaxa 4072 (3), pp. 373-383 : 375-378

Metapeachia schlenzae sp. nov.

( Figs. 1–4 , Table 1 )

Type material. Holotype: MZUSP 0 0 1927 (one specimen); Locality: Praia de Barequeçaba, São Sebastião, São Paulo, Brazil, collected 27/Jul/1976 by E. Schlenz. Paratypes: MZUSP 0 0 1928 (five specimens); Locality: Praia de Barequeçaba, São Sebastião, São Paulo, Brazil, collected 14/Oct/1978 by E. Schlenz. MZUSP 0 0 1929 (two specimens); Locality: Praia de Barequeçaba, São Sebastião, São Paulo, Brazil, collected 29/Jul/1976 by E. Schlenz. MZUSP 0 0 1930 (one specimen); Locality: Praia do Araçá, São Sebastião, São Paulo, Brazil. Collected 10/Aug/ 1987, by M.A. Mota. Additional material: MNRJ 305 (one specimen); Locality: Praia Rasa, Enseada de Manguinhos, Búzios, Cabo Frio, Rio de Janeiro, Brazil.

Material examined for comparison. Metapeachia tropica USNM 1213073 (four specimens); Locality: Cuffe Parade, Bombay, India, collected 16/Mar/1963. Metapeachia tropica USNM 1213074 (neotype; one specimen); Locality: Cuffe Parade, Bombay, India, collected 15/Mar/1963 by C. E. Cutress. Metapeachia sp. USNM 51675 (two specimens); Locality: Back Bay, Bombay, India, collected in 1958 by V.B. Tembe. Synpeachia temasek USNM 1227860 (paratype; one specimen); Locality: Changi Ferry Terminal beaches, Singapore, collected 24/Jun/ 2013 by R. Tan.

External anatomy. Body elongate, not divided into regions, column of preserved specimens 12–22 mm in diameter and 23–105 mm in height. Base end blunt, physa-like ( Fig. 1 A), with a diameter of 0.6–1.5 cm. Column beige in preserved specimens, mesenterial insertions visible as white lines ( Fig. 1 A, C). Column smooth, with no macroscopic specializations. Five out of ten specimens exhibited 16 vertical rows of cinclides in the distal half of the column ( Fig. 1 C); the remaining had no visible cinclides. Oral disc circular, same diameter as column when the latter is not contracted, to 4.0–9.0 mm. Cream-colored conchula protrudes through mouth in all specimens ( Fig. 1 B). Conchula with highly branched lobes exhibiting different degrees of development ( Figs. 1 B, 2A). Sixteen short, simple, cream-colored tentacles distributed in 2 cycles (8+8). Due to contraction of specimens, it was not possible to establish if tentacles are similar in length or not ( Fig. 1 B).

Internal Anatomy. Actinopharynx short. Single siphonoglyph forms a tube completely separated from actinopharynx, extending into the column to about 3/4 of its length. Actinopharynx attached to the siphonoglyph by a thin strip of tissue ( Fig. 3 C). Eight pairs of mesenteries, all macrocnemes, including two pairs of directives ( Fig. 3 A, B). Pair of directives associated with the siphonoglyph less developed than the rest of mesenteries (3A,B).

Same number of mesenteries proximally and distally; mesenteries more developed proximally. All specimens female, with developing oocytes from 0.083–0.103 mm in diameter. Species probably gonochoric. Mesogloea of siphonoglyph much wider than in actinopharynx (0.233mm vs. 0.073 mm, respectively). Retractor muscles diffuse and strong, extending through most of mesentery length ( Fig. 3 D). Parietal muscle strong and asymmetrical, with a separate pennon ( Fig. 3 D).

Tissue/cnida type Capsule length x width (Μm) X̅± SD N P F Cnidae. Spirocysts, basitrichs, microbasic b -mastigophores, microbasic p -mastigophores ( Fig. 4 ). For distribution and sizes, see Table 1 .

Type locality. Praia de Barequeçaba in São Sebastião, São Paulo, Brazil.

Distribution and natural history. Metapeachia schlenzae sp. nov. is known from Praia de Barequeçaba e Praia do Araçá in São Sebastião (São Paulo) and praia Rasa in Cabo Frio (Rio de Janeiro) in the southeastern coast of Brazil. This distribution may be underrepresented given the scarcity of sea anemone collections from soft sediments in Brazil. The specimens are described from museum material but according to Schlenz (1985), the specimens were not numerous and occurred solitarily burrowing in sand up to 28 cm deep in the intertidal zone. The presence of a physa-like end in all individuals and the absence of any substrate attached to it or present in the jars suggests a burrowing habit.

Etymology. The species is named after the Brazilian zoologist and cnidarian taxonomist Erika Schlenz, who collected and studied specimens of the new species.

Figures

FIGURE 1. External anatomy of Metapeachia schlenzae sp. nov. and Metapeachia tropica (Panikkar, 1938). A) Lateral view of the preserved holotype of Metapeachia schlenzae sp. nov. (MZUSP 001930) B) Oral view of a specimen of Metapeachia schlenzae sp. nov. showing the oral disc with tentacles, actinopharynx and conchula C) Detail of the column of Metapeachia schlenzae sp. nov. in horizontal position, showing cinclides D) Detail of the column in horizontal position showing cinclides of Metapeachia tropica. Scale bars A, B) 20 mm, C) 5 mm, D) 6 mm.

FIGURE 2. Morphology of the conchula A) Branched conchula of Metapeachia schlenzae. sp. nov. B) Five-lobed conchula of M. tropica (Panikkar, 1938) C) Five-lobed conchula of Peachia quinquecapitata McMurrich, 1913. Scale bars A) 2 mm, B) 4 mm, C) 6 mm.

FIGURE 3. Internal anatomy of Metapeachia schlenzae sp. nov. A) Cross section through the column at the level of the actinopharynx showing the cycles of mesenteries B) Histological cross section through the column at the actinopharynx, showing the siphonoglyph completely separated from the actinopharynx (one pair of mesenteries is missing) C) Detail of the siphonoglyph forming a tube but still attached to the actinopharynx by a small strip of tissue (arrow) D) Detail of one pair of mesenteries with the parietal muscle with a separate pennon. Abbreviations: *, directive mesenteries; Ac, actinopharynx; S, siphonoglyph. Scale bars A) 5 mm, B) 4 mm, C) 0.5 mm D) 1.0 mm.

FIGURE 4. Cnidom of Metapeachia schlenzae sp. nov. (A) Spirocyst (B) Basitrich (C) Basitrich (D) Microbasic p - mastigophore (E) Basitrich (F) Microbasic b - mastigophore (G) Microbasic p- mastigophore.

Tables

TABLE 1. Size and distribution of cnidae of Metapeachia schlenzi nov. sp. (MZUSP 0 0 1927, 0 0 1929, 001930). Measurements are in micrometers (Μm); X ̅ = mean; SD = standard deviation; N = number of capsules measured; P = proportion of specimens that showed a particular kind of cnidae; F = frequency of each type of cnidae: +++ = very common, + = not common. Frequency is a subjective estimation of the abundance of each cnidae. Abbreviation, Mic = microbasic. Letters following cnidae type refer to Fig. 4.

TENTACLES
Spirocysts (A)	19.61–30.39 x 1.96–2.94	27.07±2.00 x 2.55±0.48	129 4/4 +++
COLUMN
Basitrichs (B)	14.70–19.61 x 2.94–4.90	16.72±1.03 x 3.63±0.46	224 4/4 +++
ACTINOPHARYNX
Basitrichs (C)	15.68–23.53 x 1.96–2.95	19.07±1.45 x 2.25±0.45	196 4/4 +++
Mic. p -mastigophores (D)	24.51–35.29 x 7.84–10.78	29.56±2.34 x 9.13±0.84	114 4/4 +++
FILAMENTS
Basitrichs (E)	07.84–19.61 x 1.96–2.94	13.13±2.01 x 2.02±0.17	108 3/4 +
Mic. b -mastigophores (F)	19.61–36.27 x 3.92–7.84	24.97±2.34 x 5.31±0.70	152 4/4 +++
Mic. p -mastigophores (G)	12.74–27.49 x 4.90–7.84	21.18±1.78 x 5.63±0.67	211 4/4 +++