Phisidia rubra, Nogueira, João Miguel De Matos & Alves, Tarsila Montrezoro, 2006

Nogueira, João Miguel De Matos & Alves, Tarsila Montrezoro, 2006, Two new terebellid polychaetes (Polychaeta: Terebellidae) from the state of São Paulo, southeastern Brazil, Zootaxa 1205, pp. 31-54 : 44-52

publication ID	https://doi.org/ 10.5281/zenodo.172367
DOI	https://doi.org/10.5281/zenodo.6261657
persistent identifier	https://treatment.plazi.org/id/546D1F41-FF84-FFF5-1D40-FE7BFEBFFDBC
treatment provided by	Plazi
scientific name	Phisidia rubra
status	sp. nov.

Treatment

Phisidia rubra View in CoL sp. nov.

( Figs. 5–8 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 )

Material examined

State of São Paulo. Caraguatatuba, intertidally, on rocky shore: Praia de Martim de Sá (23º37’S, 45º23’W): 8 spec., coll. 13/03/2001; 9 spec., coll. 19/09/2001. São Sebastião, intertidally, on rocky shore: Praia do Araçá (23º49’S, 45º24’W): 1 spec., coll. 24/07/2002; 2 spec., coll. 20/07/2005; Praia Preta (23º49’S, 45º25’W), on rocky shore: 1 spec., coll. 18/ 07/2003; Praia da Baleia (23º47’S, 45º40’W), on rocky shore: 1 spec., coll. 08/04/2001.

Comparative material examined

Phisidia echuca : Australia, South Australia, Kangaroo Island: holotype (AM W 200472) and specimen AM W 200473. Australia, Victoria, Westernport Beacon: specimen NMV F52602 View Materials .

Phisidia sp.: New Zealand, Stewart Island, Big Glory Bay: two specimens.

Type series

Nine specimens, all well preserved. Holotype and paratype 3 complete specimens, remaining paratypes incomplete. Holotype and paratypes 1–2 deposited at the MZUSP (holotype: MZUSP 16927; paratypes: MZUSP 16928), paratypes 3–5 deposited at the AM (AM W29692–29694, respectively), paratypes 6–8 deposited at the ZMUC ( ZMUC – POL –1817). Holotype: coll. Caraguatatuba, Praia de Martim de Sá, 19/09/2001, 47 segments, 5 mm long, 0.5 mm wide. Paratype 1: coll. Caraguatatuba, Praia de Martim de Sá, 13/03/2001, 29 segments, 5.5 mm long, 0.4 mm wide. Paratype 2: coll. São Sebastião, Praia da Baleia, 08/04/2001, 33 segments, 7 mm long, 0.5 mm wide. Paratype 3: coll. Caraguatatuba, Praia de Martim de Sá, 19/09/2001, 45 segments, 4 mm long, 0.4 mm wide. Paratype 4: coll. Caraguatatuba, Praia de Martim de Sá, 19/09/2001, 38 segments, 5 mm long, 0.5 mm wide. Paratype 5: coll. São Sebastião, Praia Preta, 18/07/2003, 24 segments, 4 mm long, 0.6 mm wide. Paratype 6: coll. Caraguatatuba, Praia de Martim de Sá, 19/09/2001, 68 segments, 7 mm long, 0.5 mm wide. Paratype 7: coll. Caraguatatuba, Praia de Martim de Sá, 13/03/2001, 25 segments, 3.5 mm long, 0.4 mm wide. Paratype 8: coll. Caraguatatuba, Praia de Martim de Sá, 19/09/2001, 31 segments, 4 mm long, 0.3 mm wide.

Description

Body short and cylindrical, usually widest at midthorax ( Fig. 6 View FIGURE 6 C), reddish in life, white after fixation. Holotype complete, with 47 chaetigers, 5 mm in length by 0.5 mm in width, at widest point of thorax, but longer incomplete specimens were observed and included in type series (see above). Prostomium distally expanded, with up to 11 cylindrical tentacles ( Figs. 5 View FIGURE 5 A, 6A–G), longest reaching to segment 17. Laterally, basal part of prostomium with up to 4 small and frequently nearly inconspicuous eyespots ( Fig. 5 View FIGURE 5 A). Lips densely ciliated around mouth, upper lip short and rounded, lower lip small, restricted to oral area and frequently swollen ( Fig. 6 View FIGURE 6 C–G). Peristomium continuing laterally beyond lower lip for short extension, with conspicuous ciliation at border with prostomium ( Fig. 6 View FIGURE 6 D–F). Segment 1 dorsally short, ventrally expanded below lower lip ( Fig. 6 View FIGURE 6 A–G); segment 2 ventrally protruding ( Fig. 6 View FIGURE 6 C–G); segments 2–4 progressively longer ( Fig. 6 View FIGURE 6 A–B, F). Segments 1–4 progressively more inflated dorsally ( Fig. 6 View FIGURE 6 A–B, D, F). Distinct ventral shields from segment 2 until end of thorax, followed by midventral stripe ( Fig. 6 View FIGURE 6 C, G) extending until pygidium. Notopodia from segment 4 ( Figs. 5 View FIGURE 5 A, 6A–D, F–G), extending for 14 segments. On segments 4–10, chaetae on anterior row of notochaetae as thin bladed, strongly serrated capillaries ( Figs. 5 View FIGURE 5 C, 7A–B) and chateae on posterior row of notochaetae as slightly geniculate, limbate capillaries, with limbation ending subdistally and hirsute alimbate tip, with one lateral row of fine hairs ( Figs. 5 View FIGURE 5 B, 7A, C–D). From segment 11 until end of thorax, chaetae on anterior row of notochaetae as on anterior chaetigers, but with broader bases and stouter teeth, and chaetae on posterior row of notochaetae as medially limbate, distally finely serrated capillaries ( Figs. 5 View FIGURE 5 F–G, 7E –H). Neuropodia present from segment 5, glandular and sessile, slightly elevated from body wall throughout ( Figs. 5 View FIGURE 5 A, 6C–D, F–I), with internal shafts attached to uncini by ligaments on abdominal segments. Uncini avicular, with short triangular heel and developed prow, dorsal button far from anterior margin of uncini, at about midlength between base of main fang and end of prow ( Fig. 5 View FIGURE 5 D–E); uncini with about 5 irregular rows of secondary teeth above main fang ( Figs. 5 View FIGURE 5 D–E, 8 A–H). Uncini arranged in double rows from segments 11–20, three segments after cessation of notopodia ( Fig. 6 View FIGURE 6 C, G–H); rows well separated ( Fig. 8 View FIGURE 8 C), but uncini from both rows with prows aligned. Nephridial papillae ventral to notopodia, or between notopodia and neuropodia, on segments 3–8 ( Fig. 6 View FIGURE 6 I). Pygidium crenulated, without anal papillae.

Remarks

Phisidia is a conservative genus, in which most characters usually used to distinguish between species of other genera of terebellines are fixed between species. Species of Phisidia usually live among algae and similar substrata, from shallow to deep waters (Table 1). Seven species of this genus have been described so far and an eighth one, from New Zealand, will be described soon (Glasby et al. in prep.) and is treated here as Phisidia sp. The most important characters distinguishing these species are the presence and number of prostomial eyespots, the number of rows of secondary teeth above uncinial main fang, the number of segments with uncini arranged in double rows and the number of pairs of notopodia. The characteristics of each species of Phisidia are listed in Table 1.

Phisidia rubra View in CoL sp. nov. is similar to P. echuca View in CoL , P. sagamica View in CoL , P. sanctaemariae View in CoL and P. sp., as all have uncini arranged in double rows for 10 segments, on segments 11–20. In contrast, the known species of Phisidia View in CoL with different number of segments with uncini arranged in double rows are P. oculata View in CoL , which, according to the original description, has uncini arranged in double rows on segments 11 to 34 (24 segments), P. castanea View in CoL , with uncini in double rows for 9 segments, and P. rubrolineata HartmannSchröder and Rosenfeldt,1989 View in CoL and P. a u re a, both latter species with uncini arranged in double rows for 910 segments.

In addition to the number of segments on which uncini are arranged in double rows, P. aurea View in CoL differs from P. rubra View in CoL sp. nov. in being a larger species, without eyespots, with only 13 pairs of notopodia and with uncini more heavily crested, with 7 rows of secondary teeth (Table 1).

P. rubrolineata also lacks eyespots, is a larger species and has uncini more heavily crested than P. rubra sp. nov., with 6 rows of secondary teeth (Table 1). In addition, it differs from P. rubra sp. nov. in having ventral shields starting from segment 5 and body pigmentation as one reddish brown longitudinal band at each lateral of the body, starting from the penultimate thoracic chaetiger and extending through the abdomen.

Similarly, P. castanea differs from P. rubra sp. nov. in being a larger species and having 16 pairs of notopodia (Table 1). In addition, uncini of P. castanea have 3 rows of secondary teeth and prow and heel both distally rounded, instead of triangular and distally sharp, as in all other species of the genus. Finally, P. castanea has reddish brown pigmentation dorsally on segment 1 and on the posterior borders of segments 2–5, and ventrally on segment 2.

Among the species of Phisidia with uncini arranged in double rows on segments 11–20, P. echuca is distinguished from P. r u b r a sp. nov. for being a considerably larger species, for not having prostomial eyespots and for having uncini with four rows of secondary teeth (Table 1).

Phisidia sagamica View in CoL was originally described in German ( Hessle 1917) and, most probably because of problems of translation, some of its characters seem to have been misinterpreted. For example, Hessle (1917) said: “… Die drei ersten Paare Hakenborstenchaetopodien hinter den Haarborsten sind zweireihig, die folgenden sind einreihig…”, meaning this species has uncini arranged in double rows for three chaetigers after the end of notochaetae, thereafter in single rows. This was interpreted by subsequent authors (e. g., Southward 1956, Hutchings and Glasby 1988) as this species only having uncini in double rows for three segments, what would be very unusual for a terebelline. In our opinion, this sentence means this species has uncini in double rows until three segments after the end of notopodia, meaning segment 20, exactly as in P. a u re a, P. echuca View in CoL , P. sanctaemariae View in CoL and P. r u b r a sp. nov. It is unclear, however, from which segment uncini start being arranged in double rows and so it is not possible to count the number of segments with such an arrangement of uncini. In regards to eyespots, Hessle (1917) said P. sagamica View in CoL has some developed eyespots, but it is unclear how many eyespots it has and also what the author means by “developed”. Anyway, P. sagamica View in CoL has 4 rows of secondary teeth above the uncinial main fang, differing from P. rubra View in CoL n. sp. in this respect, and its typelocality is in Japan, far from Brazil (Table 1).

Phisidia sanctaemariae View in CoL differs from P. rubra View in CoL sp. nov., in lacking eyespots and having 16 pairs of notopodia and 7 rows of secondary teeth above the uncinial main fang (Table 1). Finally, P. sp. from New Zealand differs from P. rubra View in CoL sp. nov. in having many more eyespots, which form a continuous row across the prostomium, and in having a different number of rows of secondary teeth above the main fang of uncini, 4–5 rows on the anterior thoracic uncini, 3 rows on the midthoracic uncini and about 7 rows on the abdominal uncini.