The family Phoxocephalopsidae ( Crustacea : Amphipoda ) from Brazilian coastal waters with description of four new species

Phoxocephalopsids are fossorial amphipods endemic to the Southern Hemisphere and currently encompass five genera and 15 species, including the four new species herein described. Previous records of the family along the Brazilian coast are limited to Phoxocephalopsis zimmeri Schellenberg, 1931. Based on material from the Crustacean Collection of Museu Nacional/UFRJ four new species of Phoxocephalopsidae are herein described: Phoxocephalopsis ruffoi sp. nov. from Rio de Janeiro, São Paulo, Paraná and Rio Grande do Sul (23-30S); Puelche irenae sp. nov. from Espírito Santo and Rio de Janeiro (19-23S); Puelche longidactylus sp. nov. from Bahia, Espírito Santo and Rio de Janeiro (12-23S) and Puelche mourae sp. nov. found only at Rio de Janeiro. High diversity was recorded from the Campos Basin region, which extends from the north of Rio de Janeiro to south of Espírito Santo (21-23S), with the presence of all four phoxocephalid species. A key to Phoxocephalopsidae species from Brazil, including P. orensanzi Barnard and Clark, 1982 is provided.


INTRODUCTION
The family Phoxocephalopsidae Barnard and Drummond, 1982 is endemic to the Southern Hemisphere and includes amphipods ranging from 5 to 15 mm in length that live within unconsolidated substrates.Barnard and Drummond (1982) created the family Phoxocephalopsidae as part of the superfamily Haustorioidea, together with fossorial families as Condukiidae Barnard and Drummond, 1982;Haustoriidae Stebbing, 1906;Phoxocephalidae G.O. Sars, 1891; Platyischnopidae Barnard and Drummond, 1979; Urohaustoriidae Barnard and Drummond, 1982;Urothoidae Bousfield, 1978;and Zobrachoidae Barnard and Drummond, 1982.This classification was questioned by Bousfield and Shih (1994) because all these families were endemic to the Southern Hemisphere, except Haustoriidae, which inhabits coastal waters of the Northern Hemisphere.Thus, Bousfield and Shih (1994) established the superfamily Phoxocephaloidea, including only southern Hemisphere families, without the Haustoriidae.More recently, Lowry and Myers (2017) re-estabilished the superfamily Haustorioidea based on a phylogenetic analysis, with PRISCILA S. DO NASCIMENTO AND CRISTIANA S. SEREJO all families included by Barnard and Drummond (1982), including also other fossorial families as Cheidae Thurston, 1982; Ipanemidae Barnard and Thomas, 1988;Otagiidae Hughes and Lörz, 2013;Pontoporeiidae Dana, 1852;Priscillinidae d'Udekem and d'Acoz, 2006;Sinurothoidae Ren, 1999.The cold water genus Phoxocephalopsis Schellenberg, 1931 was treated as the type genus of the family erected by Barnard and Drummond (1982).Puelche Barnard and Clark, 1982 was described from Argentina, a monotypic genus until the present study and Eophoxocephalopsis Thurston, 1989 from the Falkland Islands.More recently, Sittrop et al. (2014) moved Pseudurothoe Ledoyer, 1986 andUrothopsis Ledoyer, 1967 from Urothoidae to Phoxocephalopsidae, based on the analysis of the respective type species of each genus.Therefore, the family Phoxocephalopsidae comprises five genera and 15 species, including the new species described herein: Phoxocephalopsis (6 spp.), Puelche (4 spp.), Eophoxocephalopsis (3 spp.), Pseudurothoe (1 spp.) and Urothopsis (1 spp.).The distribution of Phoxocephalopsis, Puelche and Eophoxocephalopsis is restricted to the South American coast, including Brazil, Uruguay, Argentina, Falklands Islands, Chile and the Magellan Region.Pseudurothoe and Urothopsis are found in the South Africa and Madagascar, respectively.In Brazil, only Phoxocephalopsis zimmeri Schellenberg, 1931 was previously recorded from São Paulo state (Wakabara et al. 1991, Wakabara andSerejo 1998).Ruffo (1956) worked with material from Santos, SP, which was identified as P. zimmeri.However, Ruffo (1956) presented the dactylus of pereopod five in P. zimmeri with groups of long robust setae at the inner edge, differing from the original description of Schellenberg (1931).Further works referred to Ruffo's material as a different species (Barnard and Clark 1984, Thurston 1989, Barnard and Karaman 1991), but no formal species description was provided.The present study fully describes Phoxocephalopsis ruffoi sp.nov.based on material from the Campos Basin, RJ, with additional records for the states of Paraná and Rio Grande do Sul.Material from the states of Rio de Janeiro and Espírito Santo have been examined yielding new information on the distribution of P. zimmeri.In addition, samples from Campos Basin, RJ allowed the description of three new species for the genus Puelche, with records for the states of Bahia and Espírito Santo.

MATERIALS AND METHODS
Most of the material examined was collected as part of the three projects as follows: 1. Rapid Assessment of Biodiversity -Ilha Grande Bay Program (2003) with summer sampling (from October to December) using a manual corer of 100 mm in diameter by 150 mm in height between depths of 80 and 100 m.The study area was Ilha Grande Bay (22º50' -23º20'S, 44º00' -44º45'W), south of Rio de Janeiro state, Brazil (Creed et al. 2007); 2. HABITATS Project -Environmental Heterogeneity of the Campos Basin (2008Basin ( to 2009) ) with samples collected from the continental shelf at depths of 25 to 150 m,from January to March (summer -rainy period) and from May to July (winter-dry period), using a Van Veen grab 92 × 80 × 40 cm (Ribeiro-Ferreira et al. 2017); 3. AMBES Project (2010 to 2013) -Marine environmental characterization of the Espírito Santo Basin (2010 to 2013) with samples collected on the Continental shelf from depths of 12 to 150 m , from December to February (summer) and from June to July (winter) using Van Veen grab 92 × 80 × 40 cm and Box Corer gears 50 × 50 × 50 cm.The two later projects were coordinated by CENPES/PETROBRAS (Petróleo Brasileiro S.A.) as part of the characterization of the Campos Basin and Espírito Santo Basin.Detail information on the sediment cover, bathymetry and in long setules, forming a tuft (Fig. 5d).The term "pappose setae" will be used for long shaft setae, at least half the length of shaft branched in setules, not forming a tuft.The term "robust setae" will be used (sensu Watling 1989), instead of "cuspidate setae" from Zimmer et al. (2009).All material herein examined are deposited in the Crustacea Collection of the Museu Nacional from the Universidade Federal do Rio de Janeiro (MNRJ). Abbreviations
Phoxocephalopsidade specimens from studies of spatial distribution of benthic macrofauna in beaches of Rio Grande do Sul state was also analyzed.The study areas were the beaches of  and Jardim do Éden (30º05'800'' S -50º10'238'' W), with sampling in April of 2003 using a PVC extractor tube with 20 cm diameter over transects set on each beach, from the intertidal zone down to 1.0 m depth seawards (Neves andBemvenuti 2006, 2009).
There were also analyzed samples deposited in the Crustacea Collection of the Museu Nacional from the Universidade Federal do Rio de Janeiro (MNRJ) by different collectors from the states of Bahia, Rio de Janeiro and Paraná using manual corers (from 1 to 22 m of depth).
All samples were examined and identified under a Zeiss Stemi SV6 stereomicroscope and ZEISS Axioscope coupled with a camera lucida.Specimens were dissected and mounted in semipermanent slides made with glycerin jelly.Illustrations were prepared using Inkscape 0.48 graphics program with the aid of a Wacom Intuos CTL480L pen table adapted from the methodology proposed by Coleman (2006).
There were also produced photographs on stereoscopic microscope ZEISS Discovery V.20 with coupled camera and image processing in extended depth of focus mode by ZEN Pro 2 (Blue edition) program to illustrate the habitus of Puelche species.
Coxae 1-4 progressively larger.Gnathopod 1, coxa small, shoe-shaped with small simple setae; basis and ischium with group of plumose setae on posterodistal angle; carpus with posterior tumescence and densely setose on posterior margin; propodus thinner, with simple setae distally; dactylus simple.Gnathopod 2, coxa subrectangular with small simple setae; basis longer than in G1, 7.5x longer than wide, with simple setae on anterior margin and groups of plumose setae on posterior margin; ischium with a row of long plumose setae on posterior margin; carpus and propodus with setal armament similar to G1; subchelate, palm transverse, setose, distally delimited by a robust seta, dactylus setose, reaching the end of the palm.Pereopods 3, coxa subrectangular, 1.5x longer than wide with simple setae on ventral margin; basis with long simple setae and 1 plumose seta on posterior margin; merus posterior margin toothed on distal half, with 3 groups of simple setae; carpus posterior margin with 6 robust setae with accessory seta (setal formula 3-1-2) and 2 rows of simple setae laterally; propodus with robust setae with accessory seta, 8 on one side of dactylus and 7 on the other;dactylus with distal tooth.Pereopod 4, coxa subquadrate, 1.1x longer than wide with simple setae on the ventral and posterior margins and 3 plumose setae on posteroventral angle; basis with simple setae and plumose setae on posterior margin; merus posterior margin toothed, with groups of simple and plumose setae; carpus with 5 robust setae with accessory seta on posterior margin (setal formula 2-1-2); propodus with robust setae with accessory seta, 7 on one side of dactylus and 6 on the other;dactylus with distal tooth.Coxae 5-6 bilobed, lobes subequal.Pereopod 5, basis with distal simple setae on anterior margin and short simple setae on posterior margin; ischium and merus short, with simple and robust setae on anteroventral angle; carpus and propodus with many groups of robust setae with accessory seta, posterior margin with plumose setae; dactylus anterior margin with 4 great notches with groups of robust setae on each one (setal formula 3-4-3-4) and 2 small notches without setae distally.Pereopod 6, merus, carpus and propodus anterior and posterior margins with groups of robust setae with accessory seta; merus with 1 plumose seta on each group of posterior margin; dactylus with distal tooth.Pereopod 7 longer than 6, coxa distally rounded; basis subcircular; merus, carpus and propodus with groups of simple setae and robust setae with accessory seta; dactylus longer than dactylus of pereopod 6 with distal tooth.
Epimeron 1 with a few simple setae, with a blunt posteroventral tooth; epimeron 2 strongly dominat with long plumose setae and a small posteroventral tooth; epimeron 3 poorly setose with small ventral tooth and posteroventral angle acute.Pleopods in urohaustoriid form.

Phoxocephalopsis zimmeri
Maxilliped, inner plate broad with 1 robust seta and 10 pappose setae apically, 1 of them stubby; outer plate as broad as inner plate, inner margin with 1 proximal pappose seta, many robust setae and simple setae; article 1 of palp with 1 long simple seta on inner margin; article 2 broad, with dense row of setae on inner margin; article 3 thinner than article 2, with simple setae, some with lamellate tip; article 4 rod-shaped with 2 apical robust setae.
Gnathopod 1, coxa ventrally rounded with group of 5 long simple setae; basis and isquium with posterodistal group of simple setae; carpus posteriorly tumescent, densely setose on posterior margin, with sparse row of short simple setae laterally; propodus thinner, with simple setae distally; dactylus simple.Gnathopod 2, coxa ventrally rounded; basis longer than in G1, with a few short simple setae; setose articles with simple setae most on posterior margin; chelate, palm with 4 robust setae, distally delimited by a acute projection of the propodus and 1 large robust seta, dactylus short with apical flake, inner margin medially lumpy with small simple setae.Pereopods 3, coxa 3x larger than coxa 2, subrectangular, 1.4x longer than wide, reaching about half the length of the basis, ventral angles rounded, without lobes, posterior margin with simple 8 simple setae; merus with groups of simple setae; carpus posterior margin with 10 robust setae and 2 plumose setae; propodus with robust setae with accessory seta and distal tooth surrounding dactylus (setal formula 6-1-5); dactylus with distal tooth.Pereopod 4, coxa as long as wide, reaching more than half the length of the basis, with pointed posteroventral lobe, ventral margin 6 long simple setae; basis with 2 plumose setae distally; merus with simple setae and plumose setae; carpus, posterior margin with row of simple setae and plumose setae, 10 robust setae with accessory seta and distal tooth; propodus with robust setae surrounding dactylus (setal formula 5-1-5); dactylus with distal tooth.Pereopod 5, coxa bilobed with anterior lobe larger than posterior; basis 1.3 wider than long, with groups of simple setae on anterior margin and 13 simple setae on posterior margin; ischium with group of robust setae on anterior margin; merus, carpus and propodus with groups of robust setae with accessory seta and distal tooth, posterior margins with plumose setae, carpus strongly setose on posteroventral angle; dactylus with distal tooth.Pereopod 6, coxa bilobed with posterior lobe larger than anterior; basis suboval, 1.4x longer than wide, with 2 simple setae on anteroventral angle and 8 simple setae on posterior margin; merus, posterior margin with plumose setae; merus, carpus and propodus with groups of robust setae with accessory seta and distal tooth; dactylus with distal tooth.Pereopod 7 longer than 6; coxa distally rounded; basis suboval, as long as wide, with group of simple setae on anteroventral angle and 4 simple setae on posterior margin; merus with groups of simple setae on anterior margin, plumose setae on posterior margin and 1 robust seta on posteroventral angle; carpus and propodus with groups of simple setae and groups of robust setae with accessory seta and distal tooth; dactylus with distal tooth.
Upper lip rounded, 1.2x longer than wide, with small simple setae apically.Mandibular incisors not toothed; right and left lacinia mobilis with 2 blunt teeth; rakers absent; molar broad, elongate, triturative in both sides; palp 3-articulated, similar in both sides, article 1 short, 0.3x the length of the article 2, both articles naked; article 3 0.7x the length of the article 2, with 5 distal setae with hooklike tip on the right mandible and 6 on the left mandible.Lower lip with mandibular lobes well developed, posteriorly directed.Maxilla 1, inner plate tapered, reaching about half the length of outer plate, with 1 plumose seta apically; outer plate with 10 apical robust setae weakly serrate; palp about half the length of outer plate, weakly 2-articulated, with 3 pappose setae apically.Maxilla 2, plates subequal in length and width, both with simple setae apically, inner plate with subapical row of plumose setae.Maxilliped, inner plate broad with 5 pappose setae apically, 3 of them slender and 2 stubby, 1 subapical pappose seta; outer plate broad, larger than inner plate, with robust setae and simple setae on inner margin; article 1 of palp with 1 long simple seta on inner margin; article 2 broad, with dense row of simple setae on inner margin; article 3 thinner than article 2, with simple setae, some with lamellate tip; article 4 rod-shaped with 2 apical robust setae.
Gnathopod 1, coxa small, subquadrate; carpus posteriorly tumescent, densely setose on posterior margin, with sparse row of short simple setae laterally; propodus thinner, with simple setae distally; dactylus simple.Gnathopod 2, coxa small, ventral margin rounded; basis longer than in G1, with some long simple setae, setose articles with simple setae most on posterior margin; weakly chelate, palm with 4 robust setae, distally delimited by a small acute projection of the propodus and 1 large robust seta, dactylus short with apical flake, inner margin medially lumpy with small simple setae.Pereopod 3, coxa much larger than coxae 1 and 2, subrectangular, 1.8x longer than wide, reaching the end of the basis, posteroventral lobe present with 1 simple seta and 1 plumose seta; basis with plumose setae on posteroventral angle; merus with groups of simple setae; carpus posterior margin with 4 robust setae; propodus with robust surrounding dactylus(setal formula 4-1-3); dactylus and all robust setae with accessory seta and distal tooth.Pereopod 4, coxa nearly naked, larger than 3, 1.3x longer than wide, reaching the end of the ischium, with pointed posteroventral lobe; ischium with a group of plumose setae on posterior margin; merus with simple setae and plumose setae distally; carpus posterior margin with 3 robust setae; propodus with robust setae seta surrounding dactylus, (setal formaula 3-1-3); dactylus and all robust setae with accessory seta and distal tooth.Pereopod 5, coxa bilobed with anterior lobe larger than posterior; basis 1.6x wider than long, with 2 long simple setae on anteroventral angle and posterior margin with 6 plumose setae densely setulose; ischium, merus, carpus and propodus with groups of robust setae with accessory seta and distal tooth, posterior margins with plumose setae; dactylus as long as propodus, styliform, with accessory seta and distal tooth.Pereopod 6, coxa bilobed with lobes subequal; basis subrectangular, 1.3x longer than wide, with 2 simple setae on anteroventral angle and posterior margin with 11 plumose setae densely setulose; merus, posterior margin with plumose setae; merus, carpus and propodus with groups of robust setae with accessory seta and distal tooth; dactylus long, rod-shaped with 3 long simple setae apically.Pereopod 7 longer than 6; coxa bilobed with posterior lobe larger than anterior; basis subrectangular, 1.5x longer than wide, with 2 simple setae on anteroventral angle and posterior margin with 14 plumose setae densely setulose; merus and carpus with plumose setae on posterior margin; merus carpus and propodus with groups of robust setae with accessory seta and distal tooth; dactylus long, rod-shaped with 4 long simple setae apically.
Upper lip rounded, as long as wide, with small simple setae apically.Mandibular incisor not toothed; right lacinia pointed, 1-toothed, left lacinia mobilis with 3 teeth; rakers absent; molar broad, elongate, strongly triturative in both sides; palp 3-articulated, similar in both sides, article 1 short, 0.2x the length of the article 2, both articles naked; article 3 0.8x the length of the article 2, with 5 distal setae with hooklike tip on the right mandible and 6 on the left.Lower lip with mandibular lobes well developed, posteriorly directed.Maxilla 1, inner plate tapered, reaching about half the length of outer plate, with 1 plumose seta apically; outer plate with 10 apical robust setae weakly serrate; palp about half the length of outer plate, weakly 2-articulated, with 3 pappose setae apically.Maxilla 2, plates subequal in length and width, both with simple setae apically, inner plate with 1 large plumose seta on inner margin.Maxilliped, inner plate thin with 4 pappose setae apically; outer plate broad, inner margin with 1 proximal pappose seta, many robust setae and simple setae, 3 long simple setae facially, close outer margin; article 1 of palp naked; article 2 broad, with dense row of setae on inner margin; article 3 thinner than article 2, with simple setae with lamellate tip; article 4 of the palp rod-shaped, apex with 1 robust seta and 1 simple seta with lamellate tip.Gnathopod 1, coxa very small, subquadrate; carpus with posterior tumescence, densely setose on posterior margin, with sparse row of short simple setae laterally; propodus thinner, with simple setae distally; dactylus simple.Gnathopod 2, coxa very small, ventral margin rounded; basis longer than in G1, with many long simple setae posterior margin; setose articles with simple setae most on posterior margin; weakly chelate, palm with 4 robust setae, distally delimited by a small acute projection of the propodus and 2 large robust setae, dactylus short with apical flake, inner margin medially lumpy with small simple setae.Pereopod 3, coxa much larger than coxae 1 and 2, subrectangular, 1.8x longer than wide, reaching about half the length of the basis, with anteroventral lobe, with 1 long simple seta on posteroventral angle; merus with groups of simple setae; carpus, posterior margin with 4 robust setae with accessory seta and distal tooth and 1 plumose PRISCILA S. DO NASCIMENTO AND CRISTIANA S. SEREJO seta; propodus with robust setae with accessory seta and distal tooth surrounding dactylus (setal formula 3-1-3); dactylus with distal tooth.Pereopod 4, coxa nearly naked, as long as wide, reaching less than half the length of the basis with rounded anteroventral lobe; merus with simple setae and plumose setae distally; carpus posterior margin with 3 robust setae and row of plumose setae; propodus with robust setae surrounding dactylus (setal formula 3-1-3); dactylus and all robust setae with accessory seta and distal tooth.Pereopod 5, coxa bilobed with anterior lobe larger than posterior; basis as long as wide, with groups of simple setae and robust setae on anterior margin and 6 long plumose setae on posterior margin; ischium short and naked; merus, posterior margin with simple setae; carpus and propodus with plumose setae on posterior margins, most of them on posteroventral angle of carpus; merus, carpus and propodus with groups of robust setae with accessory seta and distal tooth; dactylus with distal tooth.Pereopod 6, coxa bilobed with anterior lobe larger than posterior; basis suboval, 2x longer than wide, with 8 simple long setae on posterior margin; merus, posterior margin with simple long setae; merus, carpus and propodus with groups of robust setae with accessory seta and distal tooth; dactylus with distal tooth.Pereopod 7 longer than 6; coxa distally rounded; basis 1.7x longer than wide, with group of simple setae on anteroventral angle and posterior margin with 5 plumose setae densely setulose; merus with groups of simple setae on anterior margin, anteroventral and posteroventral angles each one with 1 robust seta with accessory seta and distal tooth; carpus with groups of simple setae and groups robust setae with accessory seta and distal tooth; propodus with distal group of robust setae with accessory seta and distal tooth; dactylus with distal tooth.