Peresiella Harmelin 1968
Creators: name: Silva, Camila Fernanda Da
name: Amaral, Antonia Cecilia Zacagnini
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Capitellidae
Peresiella

description: Genus Peresiella Harmelin, 1968, amended
Type species: Peresiella clymenoides Harmelin, 1968: 256, figs 1–9.
Type locality: Mediterranean Sea
Generic diagnosis. (amended after Magalhães & Blake 2020). Anterior end variable, may be modified as cephalic plate or having short, conical prostomium, palpode present; eyespots present or absent, when present in multiple spots. Peristomium clearly distinct from prostomium; achaetous segment absent. First chaetiger uniramous. Eleven thoracic chaetigers. Chaetigers 1–3 with only capillaries; modified spatulate chaetae on all remaining thoracic chaetigers, up to chaetiger 10 or on chaetigers 4 and 5 only; remaining thoracic chaetigers with capillary chaetae or hooded hooks. Transition between thorax and abdomen can be clearly demarcated or subtle. Abdominal segments with only hooded hooks or modified (“transitional”) on anterior abdomen. Poorly developed neuropodial lobes. Branchiae present or absent, when present, as simple expansions of notopodia. Genital pores and lateral organs not observed. Pygidium not observed.
Remarks. The genus Peresiella is peculiar because it presents modified spatulate chaetae in the thorax in addition to the winged capillaries. These spatulate chaetae are most likely modified hooded hooks and have shaft and hood sometimes with hairlike extensions. There are currently four valid species, P. clymenoides Harmelin, 1968, P. acuminatobranchiata Thomassin, 1970, P. spathulata Ewing, 1984, and P. platyalia Green, 2002. The genus was originally introduced by Harmelin (1968) with the description of P. clymenoides from subtidal areas of the Mediterranean Sea. Harmelin (1968) named this species clymenoides because the head of the specimens resembled the cephalic plate of maldanid polychaetes. The distribution of the modified chaetae and hooded hooks varies among Peresiella species. P. clymenoides was described as having capillaries on chaetigers 1–3 and spatulate chaetae on remaining thoracic chaetigers. Two years later another species was described by Thomassin (1970), P. acuminatobranchiata, collected on shallow waters from Tulear, Madagascar, Indian Ocean. This species differed from the former by the absence of the cephalic plate, modified chaetae only on chaetigers 4 and 5 with capillaries on remaining thoracic chaetigers, and presence of branchiae. In 1984, Ewing made a revision of the genera and described the species P. spathulata, collected on subtidal regions from the Gulf of Mexico. On his revision, Ewing (1984) created the generic diagnosis for Peresiella and provided a key to the three known species. A fourth species was described by Green (2002) based on specimens collected by the BIOSHELF project on the Andaman Sea, Thailand. Peresiella platyalia has capillary setae on chaetigers 1–3, modified spatulate setae on seven thoracic segments (chaetigers 4–10), and hooded hooks on chaetiger 11. Green (2002) also provided a key to all described species. In this study, the diagnosis was modified to include a variation observed on the new species such as subtle transition between thorax and abdomen, not clearly demarcated. We also intended to include some characters shared by all species such as poorly developed neuropodial lobes and presence of palpode, which can be seen by drawing plates, but it was not mentioned by none of the previous authors.
description: Published as part of Silva, Camila Fernanda Da & Amaral, Antonia Cecilia Zacagnini, 2022, Capitellidae (Annelida) from the Brazilian Continental Margin (SW Atlantic): new occurrences of three genera and description of new species, pp. 89-110 in Zootaxa 5104 (1) on pages 98-99, DOI: 10.11646/zootaxa.5104.1.5, http://zenodo.org/record/6258005