Tanaidacea from Brazil . III . New records and description of a new species collected from REVIZEE-NE Program

A new species of Paratanais Dana, 1852, Paratanais coelhoi sp. nov., is described and new records for Paradoxapseudes intermedius (Hansen, 1895), Intermedichelia gracilis Guţu, 1996, Vestigiramus sp., Nototanoides cf. trifurcatus Sieg and Heard, 1985, Biarticulata sp. and Arhaphuroides sp. are provided from northeastern Brazil based on collections from the REVIZEE-NE Program. This raises the number of tanaidacean species from the Brazilian coast from 45 to 49. Paratanais coelhoi sp. nov. shares morphological features such as habitus shape, maxilliped palp setation, and cheliped proportions with P. oculatus (Vanhöffen, 1914), P. martinsi Bamber and Costa, 2009, P. tara Bird, 2011 and P. euelpis Barnard, 1920. The new species can, however, be distinguished by a unique combination of characters including: pleonites 1–4 with lateral circumplumose setae while the 5th with simple seta only; antennule article 1 stout; cheliped propodus with one specialized outer ‘S’-shaped broad seta; pereopod 1 merus length with 1.7 times as long as wide; pereopod 2 merus without ventral spiniform seta; uropodal endopod biarticulate, exopod uniarticulate as well as other characters.

At the end of the twentieth century (1995)(1996)(1997)(1998)(1999)(2000) the REVIZEE Program (Programa de Avaliação do Potencial Sustentável dos Recursos Vivos da Zona Econômica e Exclusiva do Brasil), a survey of the fauna and flora of the exclusive economic zone of the coast of Brazil, was conducted.During this program, collections were made on northeastern coast (NE Score) along the continental shelf and oceanic banks of the Archipelago of Fernando de Noronha and North Chain Banks of Brazil.These collections revealed a number of members of several of tanaidacean families, including the Apseudidae Leach, 1814;Leptocheliidae Lang, 1973;Leptognathiidae Sieg, 1976;Metapseudidae Lang, 1970;Nototanaidae Sieg, 1976;Paratanaidae Lang, 1949 andTanaellidae Larsen andWilson, 2002.The family Paratanaidae currently contains five genera and occurs in both deep (Bathytanais Beddard, 1886 andPseudobathytanais Kudinova-Pasternak, 1990) and shallow waters (Bathytanais; Paratanais Dana, 1852;Triparatanais Bamber and Chatterjee, 2010;Xeplenois Bamber, 2005), but the majority of species are from shallow water.Bird and Larsen (2009) regarded Paratanaidae as one of the few monophyletic families that has remained stable since its establishment and probably the only one that is not controversial.The genus Teleotanais Lang, 1956 was assigned by Bamber (2008) to a new subfamily principally on the basis of 1-4 circumplumose epimeral pleonal setae; however, this genus is unlike any paratanaid and appears more leptocheliid-like, and it was raised to familylevel by Bird and Larsen (2009).
The main diagnostic characters of the family Paratanaidae are the presence of maxilliped endites laterally expanded and wider than basis; pereopod 4-6 carpus with clinging apparatus present as strong spiniform setae and scales (complex or not) but without microtrichial field; pleonites 1-5 (or 1-4) with lateral circumplumose setae (Bird and Larsen, 2009: 155), as well as other characters.Even though these characters seem to be consistent, Sieg (1986: 57) stated that the systematic of the genus Paratanais is quite confusing, and that a revision was required.Such a revision is currently under way (G.J. Bird, pers. comm.).
The genus Paratanais is represented on the Brazilian coast by P. oculatus and was first recorded by Silva-Brum (1973: 4-5) from Bahia (northeastern Brazil) but this identification is uncertain (see remarks of P. coelhoi sp.nov.).In this study, a new species of Paratanais is described and new records are provided for Nototanoides cf.trifurcatus Sieg and Heard, 1985, Biarticulata sp., Arhaphuroides sp., Paradoxapseudes intermedius (Hansen, 1895), Intermedichelia gracilis Guţu, 1996 and Vestigiramus sp., thus increasing the number of tanaidacean species known from the Brazilian coast from 45 to 49.This is the third study on the systematics of the Tanaidacea from Brazil and the first of a series of papers based on the REVIZEE-NE Program collection from the northeastern part of Brazil.

Material and Methods
Specimens were collected from the continental shelf between the mouth of Parnaíba River (Piauí state) and Salvador (Bahia state) during the expeditions Northeast Score I, II, III and IV (NE I, II, III and IV) (1995)(1996)(1997)(1998)(1999)(2000); these collections were funded by the Brazilian Government and conducted from the RV 'Antares' (Directorate of Hydrography and Navigation).The material was collected using a dredge with a mesh size of 0.5 mm and capacity of about 70 l of sediment.
Body length was measured from the anterior margin of the rostrum to the tip of the telson in lateral view to avoid bias from a flexed body posture.Body width was measured on the widest part of the carapace in dorsal view.Terminology follows Larsen (2003).Adjectives such as short and long are quantifies relative to the appendages on they are located.Dissections were made with chemicallysharpened tungsten wire needles and then placed on slides with glycerine, covered by a cover slip and sealed with nail polish.Wholeanimal illustrations were made from holotype while appendages were dissected and drawn from paratypes via a camera lucida attached to a Leica compound microscope.Type material are kept at the Carcinological Collection of the 'Museu de Oceanografia Petrônio Alves Coelho', Universidade Federal de Pernambuco, Recife, Brazil (MOUFPE).
Cephalothorax: about 1.2 times as long as wide, naked.Rostrum blunt and rounded at tip.
Antennule (Fig. 1I): article 1 stout, about 1.3 as long as wide, outer distal margin with four setulated and two simple setae, one simple seta on inner distal margin.Article 2 about 0.4 times as long as wide, with two setulated setae on inner distal margin.Article 3 naked, about 0.6 times as long as wide.Article 4 slender, about 0.9 times as long as article 1 and 3.1 times as long as wide, with one outer distal simple seta.Article 5 minute, with one simple seta and two aesthetascs on distal margin.
Antenna (Fig. 1J): article 1 short, with one simple seta on inner distal margin.Article 2 about 1.2 times as long as wide, with one tiny spiniform seta on outer distal margin and one simple seta on inner distal margin.Article 3 about 0.6 times as long as article 2, with one long spiniform seta on outer distal margin.Article 4 longest, about 2.5 times as long as wide, with one pair of setulated setae on each distal margin.Article 5 with two simple setae on outer distal margin.Article 6 minute (hardly visible), with three long simple setae on distal margin.-H): labrum (Fig. 1H) typical of genus, rounded with several fine simple setae distally.Mandibles (Figs. 1C,  D) left mandible molar process with notch in the middle and two 'tooth-like' projections in middle; right mandible with molar process broad and denticles on distal margin.Left mandible (Fig. 1C) incisor as long as lacinia mobilis with six distal denticles, lacinia mobilis flattened with eight distal denticles.Right mandible (Fig. 1D) incisor broad, with seven denticles on distal margin.Labium (Fig. 1E) with fine simple setae on anterior and lateral margins.Maxillule (Fig. 1G) slender, palp uniarticulate (not illustrated).Endite with fine setae on outer and ventral margins, with seven spiniform setae on distal margin.Maxilliped (Fig. 1F) endite broad, with short spines (hardly visible) and one fine simple seta on outer distal margin, inner distal margin with two flattened setae and one long simple seta.Basis with one distal simple seta.Palp article 1 naked, about 1.2 times as long as wide; article 2 slightly longer than article 1, with one simple seta on outer distal margin and three inner distal simple setae which distal one stouter (spiniform serrated seta absent); article 3 with three bipinnate setae on inner distal margin; article 4 short, inner distal margin with five bipinnate setae and four fine setae, one outer distal simple seta.Epignath not recovered.

Mouthparts (Figs. 1C
Cheliped (Fig. 1K): attached via triangular sclerite (not illustrated).Basis short, with one dorsodistal simple seta, about 1.2 times as long as wide.Merus triangular, with one ventromedial simple seta.Carpus about 1.8 times as long as wide, dorsal margin with one proximal and one distal simple seta, one pair of ventromedial simple setae.Propodus with one 'S'-shaped broad outer distal seta, inner margin with one bipinnate seta and a row of fine setae.Dactylus with one dorsal simple seta, unguis slightly curved internally.Fixed finger with two ventral simple setae, inner margin with five denticles and three simple setae.Unguis well developed.
Pereopod 1 (Fig. 2A): coxa with one simple seta.Basis slender, about 3.4 times as long as wide, with one dorsoproximal simple seta.Ischium with one ventral simple seta.Merus about 1.7 times as long as wide, as long as carpus, with one ventrodistal simple seta.Carpus with two dorsodistal simple setae and one ventrodistal simple seta.Propodus about 3.1 times as long as wide, with two dorsodistal simple setae and one ventrodistal simple seta.Dactylus and unguis combined as long as propodus.Unguis about twice as long as dactylus.
Pereopod 2 (Fig. 2B): coxa as pereopod 1. Basis about 2.7 times as long as wide, with one dorsoproximal simple seta.Ischium as pereopod 1. Merus short, about 1.2 times as long as wide, with two ventrodistal simple setae (spiniform seta absent).Carpus as long as merus, each distal margin with one spiniform and one simple seta.Propodus about 2.5 times as long as wide, with one simple seta on dorso and ventrodistal margins.Dactylus and unguis as pereopod 1.
Pereopod 4 (Fig. 2D): no visible coxa.Basis naked, robust, about 1.8 times as long as wide.Ischium with two ventral simple setae.Merus ventrodistal margin with a row of fine setae and two spiniform setae.Carpus as long as merus, with one dorsodistal simple seta and two spiniform setae on each distal margin, at least two of which have medial ring of spinules.Propodus about 2.6 times as long as wide and 1.8 times as long as dactylus and unguis combined, with one dorsomedial setulated seta and one dorsodistal spiniform seta as long as dactylus and unguis combined, one shorter ventrodistal spiniform seta.Dactylus and unguis combined shorter than previous pereopods.Unguis short and incompletely fused with dactylus.
Endopod biarticulate; article 1 with one simple seta; article 2 with six distal simple setae.Exopod uniarticulate, about 1.2 times as long as article 1 of endopod, with two distal simple setae.
Remarks: Silva-Brum (1973: 4) observed differences on the molar process and endite of maxilliped between P. oculatus (sensu Silva-Brum, 1973) and P. oculatus (sensu Vanhöffen, 1914).However, the author considered these features insufficient to erect a new species or synonymize P. euelpis Barnard, 1920 as suggested by Lang (1950: 360).It is somehow a bit confusing why the author considered the specimens from Brazil as P. oculatus sensu stricto (Vanhöffen, 1914) and not P. euelpis if we take into account their geographic distribution.
To separate P. oculatus (sensu Vanhöffen, 1914) and P. euelpis, Sieg (1986: 57) remarked that both species are distinct by the length merus of pereopod 1 and the shape of the distolateral margin of the maxillipedal endite; the author also considered P. oculatus (sensu Silva-Brum, 1973) a misidentification, based on the distribution of P. oculatus, since the species was only recorded from the Subantarctic (Kerguelen and Falkland Islands) and Indian Ocean while P. euelpis from Cape Town (South Africa) and Morocco (Monod, 1925: 65).Currently, Bird (2011) regards the records of P. oculatus in New Zealand waters by Sieg (unpubl.data) as unconfirmed.
Considering their distribution it seems unlikely that they are the same species, however, until a close examination of the material we will here consider the species remarked by Silva-Brum (1973) as P. oculatus.
Recently Bird (2011) regarded that most of the species assigned to the genus Paratanais do not conform to the pattern set by the type species P. elongatus (Dana, 1849) with respect to pereonite proportions, pleonal plumose setation (1-4), cheliped shape and pereopod setation.Our observations confirm this differences (see Tab. 1).
Paratanais spinanotandus Sieg, 1981 is recorded for South Africa (Seamount Vema), but is easily distinguished from P. coelhoi by the serrate spiniform seta [referred as 'spine' by Sieg (1981)] on the article 2 of the maxillipedal palp, by the proportion of the P1 merus (3.9 times as long as wide), and by the uropodal exopod length relative to that of endopod article 1.It is possible that P. oculatus (sensu Silva-Brum, 1973) is conspecific with P. coelhoi, but the specimens are kept on 'Museu Nacional do Rio de Janeiro' (MNRJ) and could not be obtained for this study.
There are a few anomalies regarding P. impressus Kussakin and Tzareva, 1972.The authors figured the pereon with seven pereonites which is clearly a fusion of the cephalon with first pereonite.

Remarks:
The specimens were dredged between 40.5 and 51 m depth, and were sorted from algae and sponges.The individuals correspond to the original description, except for the cephalothorax width being slightly wider than first pereonite and antennule with 16 articles in the outer flagellum (seven in Paradoxapseudes intermedius sensu Guţu, 2008).This is the first record of P. intermedius from northeastern Brazil.

Remarks:
The specimens examined in this study were dredged between 70.8 to 71.6 m depth, from sandy sediments, and were sorted from algae and sponges.Intermedichelia gracilis is endemic to Brazilian waters and this is the first record of the species from northeastern Brazil.

Geographic distribution: Northwestern
Atlantic: the coast off Texas.The species is widespread in the northern Gulf of Mexico but with apparently patchy distribution (Larsen, 2005: 268).Southwestern Atlantic: off Ceará state, North Chain Banks, Brazil (present study).
Remarks: The specimens were dredged in 56.7 m depth, gravel bottom, temperature 28°C and salinity 36.The two individuals examined are damaged, but when compared with the characters described by Sieg and Heard (1985) and Larsen (2005) shows that the specimens are at least closely related.The differences from the original species are the anterior spiniform projection on eyes lobes and the conformation of the pleotelson (Figs.5A, B), which is more expanded than in Nototanoides trifurcatus sensu Sieg and Heard, 1985.This is the first record of N. trifurcatus from Brazil, indeed the first record for the entire South Atlantic.
Family Tanaellidae Larsen and Wilson, 2002 Genus
long as wide in Arhaphuroides sp.(about 4.6    times in A. septentrionalis); 2) antennule article 1 about twice as long as wide in Arhaphuroides sp.(about 2.5 times in A. septentrionalis); 3) cheliped propodus, fixed finger and dactylus with several tubercles (Fig.3D) (absent in A. septentrionalis); 4) uropod endopod uniarticulate, about 6.7 times as long as exopod in Arhaphuroides sp.(about 2.2 times in A. septentrionalis).This is the first record of the genus Arhaphuroides from Brazilian waters.
Bamber, 2008mber, 2008, P. martinsi Bamber and Costa,  2009 and P. vicentetis Larsen, 2012.However it can be distinguished by these and other closely related species as P. euelpis, P. oculatus
Sieg and Dojiri (1989)86Arhaphuroides sp.The individual was collected at 35 m depth.This specimen is closely related to Arhaphuroides io(Bamber, 2005)and A. septentrionalisSieg and Dojiri (1989)with type locality in Esperance Bay (Western Australia) and coast of New Jersey (NW Atlantic), respectively.Despite the overall similarity, A. io has a longer and 'sharper' exopod and a shorter endopod (Arhaphuroides sp.uropod endopod 3.2 times as long as wide); no tubercles on cheliped propodus while is evident in Arhaphuroides sp. as well as other characters.
Remarks: Arhaphuroides septentrionalis is distinct from Arhaphuroides sp. by the following characters: 1) pleonites about three times as