A new genus of Ectinosomatidae ( Copepoda , Harpacticoida ) from sublittoral sediments in Ubatuba , São Paulo State ( Brazil ) , an updated key to genera and notes on Noodtiella Wells , 1965

Both sexes of a new genus and species of Ectinosomatidae (Copepoda, Harpacticoida) from sublittoral sediments collected on the inner continental shelf in Ubatuba, São Paulo State (Brazil) are described in detail. Chaulionyx gen. n. (type species: C. paivacarvalhoi sp. n.) diff ers from all known genera in the presence of a conspicuous bifi d spine on the prehensile P1 endopod. It can be diff erentiated from other genera with a prehensile endopod (Halophytophilus Brian, 1919; Bradyellopsis Brian, 1925; Klieosoma Hicks & Schriever, 1985) by the presence of distinctive subrectangular middorsal pores on the urosomites and the unarmed male sixth legs. Th e genus Lineosoma Wells, 1965 is recognized as a paraphyletic taxon and relegated to a junior subjective synonym of Noodtiella Wells, 1965. Arenosetella pectinata Chappuis, 1954a is removed from its fl oating position in Ectinosomoides Nicholls, 1945, transferred to the genus Noodtiella as N. pectinata comb. n. and considered the senior subjective synonym of N. toukae Mitwally & Montagna, 2001. Dichotomous keys are provided for the identifi cation of the 18 valid species of Noodtiella and the 21 valid genera of the family Ectinosomatidae. Halophytophilus aberrans Wells & Rao, 1987 is placed species incertae sedis in the family.


Introduction
Th e harpacticoid family Ectinosomatidae is morphologically distinctive and arguably the most speciose group of copepods in marine meiobenthic communities.Th e taxonomic literature about this taxon is however, plagued by the scarcity of adequate species descriptions which poses a serious deterrent to most systematists and ecologists.In addition, the scale of variability exhibited by most described species is not well understood, males are frequently rare or completely unknown, distinctions between species and at least some genera are often debatable, and existing identifi cation keys for the larger genera Ectinosoma Boeck, 1865, Halectinosoma Vervoort, 1962and Pseudobradya Sars, 1904 are all essentially unreliable.Th e urgent need of revision of these genera is substantially hampered by the lack of type material and by the fact that some unverifi able descriptions undoubtedly contain important errors (Wells 2007).Recent work has demonstrated that some descriptions contain important observational errors and, consequently, some species have been attributed to the wrong genus (Clément andMoore 1995, 2000;Huys and Bodin 1997;Clément and Ólafsson 2001;Wells 2007).Th e recent recognition of species complexes (Clément and Moore 1995, 2000, 2007) refl ects the previous ignorance of characters that have not been given the attention they deserved, such as mouthpart features and body ornamentation patterns.Hence the wide geographical distributions displayed by some ectinosomatids should not be uncritically accepted as the natural consequence of potentially transoceanic or equivalent long-distance dispersal since many of the published ectinosomatid records are probably incorrect.
Th e family Ectinosomatidae appears to have had a complex ecological radiation.Th e present day habitat utilization of most primitive genera suggests that it originated in the shallow marine environment where radiation, speciation and diversifi cation appeared to be most successful.Most Ectinosomatidae are found in sublittoral marine sediments ranging from coarse sands to fl occulent muds but literature data indicate that several independent freshwater incursions occurred during the evolutionary history of the family.Within the speciose, primarily marine genus Halectinosoma, at least four species have colonized freshwater habitats in Laurasia: H. abrau (Krićagin, 1878), H. concinnum (Akatova, 1935), H. japonicum (Miura, 1964) and H. uniarticulatum Borutzky, 1972.Th e genus Pseudectinosoma Kunz, 1935 appears to have descended from a coastal brackish water ancestor and primarily inhabits karstic springs, bores, wells, phreatic lakes and hyporheic habitats in Europe and Australia (Galassi et al. 1999;Karanovic 2006).A third freshwater incursion was reported by Karanovic and Pesce (2001) who described Rangabradya indica from subterranean waters in India.Various other ectinosomatid species have been recorded in low salinity habitats but at least for some of them the generic placement needs re-evaluation (e.g.Miura 1962Miura , 1964;;Štěrba 1968;Bruno and Cottarelli 1999;Bruno et al. 2003).
Although the majority of ectinosomatids have been described from the continental shelf and the intertidal zone, various species of Halectinosoma, Bradya Boeck, 1873 andParabradya Lang, 1944 have secondarily radiated into the deep sea (Bodin 1968;Seifried et al. 2007) and recent research (Gheerardyn et al. 2008) suggests that many other genera have achieved the same habitat shift.Others, such as species of Arenosetella Wilson, 1932, Glabrotelson Huys, 2009and Noodtiella Wells, 1965 are found on the other end of the bathymetric spectrum, being frequently the only harpacticoids occurring in the infra-and supralittoral zones of sandy beaches (Mielke 1976).In beaches and sandy sublittoral habitats various genera have colonized the interstitial environment, either by adopting a cylindrical body shape (Arenosetella, Ectinosomoides Nicholls, 1945, Glabrotelson, Lineosoma Wells, 1965, Noodtiella, Oikopus Wells, 1967) or by simple miniaturization of the ancestral fusiform body (Sigmatidium Giesbrecht, 1881).Finally, some ectinosomatid lineages are no longer associated with the ancestral benthic habitat but have moved into the open pelagic or have abandoned their essentially free-living lifestyle.Th e holoplanktonic genus Microsetella Brady & Robertson, 1873 is known to attach and feed on discarded and occupied larvacean houses (Appendicularia) (Alldredge 1972;Ohtsuka et al. 1993) while other taxa have entered into associations with invertebrates.Examples of the latter include Peltobradya bryozoophila Médioni & Soyer, 1968, which appears to be associated with the bryozoan Schizomavella linearis (Hassall, 1841) (Médioni and Soyer 1968), and an as yet undescribed genus which was found in the mucus coat surrounding the polychaete host Hydroides elegans (Haswell, 1883) (Huys unpubl.).
Excellent recent studies by Mielke (1979Mielke ( , 1981Mielke ( , 1986Mielke ( , 1987a-b) -b) have contributed substantially to our knowledge of Central and South American Ectinosomatidae.However, the fauna along the vast Brazilian coastline remains poorly known (Reid 1998).Jakobi (1954) described three species of Pseudobradya and two species of Ectinosoma from Paraná State.Unfortunately, his descriptions are essentially inadequate and Lang (1965) suggested ranking all of them as species inquirendae while Wells (2007) listed them as species incertae sedis.Th e species described by Jakobi and Nogueira (1960) as Ectinosoma couceiroi is a likely synonym of E. dentatum Steuer, 1940(Lang 1965: 17) and has thus far been recorded only from the Lagoa de Conceição in Santa Catarina State.Rouch (1962) described two new species, Noodtiella problematica and Halectinosoma arenicola, from sandy beaches in Pernambuco State and listed the fi rst South American record of the allegedly cosmopolitan Arenosetella germanica Kunz, 1937.During the course of a meiofaunal survey off Ubatuba (São Paulo State) we discovered several new species of the Ectinosomatidae.One of these represented the most abundant harpacticoid copepod in the area and is described here as a representative of an as yet unknown genus, raising the number of valid genera in the family to twenty-one (Seifried et al. 2007;Wells 2007;Huys 2009).

Material and methods
Sediment samples were obtained during an ecological study of the meiofaunal diversity along the northern coast of São Paulo State as part of the interdisciplinary project "Utilização Racional do Ecossistema Costeiro da Região Tropical Brasileira: Estado de São Paulo" conducted by the Departamento de Oceanografi a Biológica -Instituto Oceanográfi co da Universidade de São Paulo (IOUSP).Samples were collected at 12 stations along the inner continental shelf (15-53 m depth) between São Sebastião Island and Ubatumirim inlet, Ubatuba, in March and August, 1989.Description of the sampling methodology and physical and chemical analysis is given by Corbisier (1993).Coordinates and environmental parameters of the stations where the new genus occurred are compiled in Table 1.
Before dissection, the habitus was drawn from whole specimens temporarily mounted in glycerine.Adhesive plastic discs were used to support the coverslip in temporary mounts.Specimens were dissected in lactic acid and the dissected parts were mounted on slides in glycerine.Preparations were sealed with transparent nail varnish.All drawings were prepared using a camera lucida on a Zeiss Axioskop 2 Plus diff erential interference contrast microscope.Total body length was measured from the anterior margin of the rostrum to the posterior margin of the caudal rami.Th e descriptive terminology is adopted from Huys et al. (1996).Abbreviations used in the text are: ae, for aesthetasc; P1-P6, for swimming legs 1-6; exp, enp and benp for exopod, endopod and baseoendopod, respectively; exp (enp)-1 (-2, -3) denotes the proximal (middle, distal) segments of a ramus.Th e term 'acrothek' denotes the trifi d setal structure found on the apical margin of the distal antennulary segment (Huys and Iliff e 1998).Type material is deposited in the collections of the Museu de Zoologia, Universidade de São Paulo (MZUSP) and the Natural History Museum, London (NHM).
Caudal rami  about as long as wide, with 7 naked setae; bases of terminal setae covered by rounded membranous serrate extension dorsally (Figs 4,30,34) and an acuminate lappet ventrally (Fig. 5).Seta I minute, with bifi d apex.Setae IV-V fused basally, without fracture planes.Seta V longest and swollen in proximal half.Seta VII tri-articulate at base.
Maxillule (Fig. 13) with fused praecoxa and coxa.Praecoxa with well developed arthrite bearing 4 spines and 1 seta around distal margin and 2 small setae on anterior surface; distalmost marginal spine with long spinules.Coxa represented by small seta on anterior surface near articulation with palp.Endopod incorporated into basis forming elongate segment; proximal basal endite a small protuberance bearing 3 setae; elements of distal basal endite (4) and endopod (3) forming group of 7 setae arranged around the distal margin; with cuticular reinforcement (indicated by asterisk in Fig. 13) on posterior surface; distal medial margin with characteristic spinules.Exopod a free small segment; with 1 apical and 1 backwardly directed plumose seta.
P5 (Figs 20,35).Baseoendopod outer expansion with 1 naked seta.Endopodal lobe with spinular row and small pore on anterior surface; with 2 naked setae, inner one very long (3.2 times longer than outer one) and with bifi d apex, outer one with serrate apex.Exopod with 1 pore near distal inner margin and various spinule rows as fi gured; anterior surface with 1 naked seta; with 3 marginal setae, innermost one with bifi d apex.
Caudal ramus (Fig. 23) with both dorsal and ventral posterior margin produced into triangular extension covering bases of setae IV-VI.
Etymology.Th e new species is named in honour of Prof. João de Paiva Carvalho (Instituto Oceanográfi co, Universidade de São Paulo) in recognition of his signifi cant contributions to the taxonomy of Copepoda.

Discussion
Th e form of the maxilla is of high signifi cance in assessing phylogenetic relationships within the family Ectinosomatidae.Two types can be distinguished on the basis of the shape and orientation of the allobasis.In the fi rst type the maxilla is stenopodial (nonprehensile) with the syncoxa, allobasis and endopod arranged in a virtually rectilinear sequence.Th is arrangement is displayed in Ectinosoma, Halectinosoma, Rangabradya, Microsetella and the interstitial genera Arenosetella, Glabrotelson, Microsetella, Ectinosomoides and Oikopus.In the second type the syncoxa and allobasis are directed at a right angle, forming a prehensile limb.Th e articulation between these two segments is modifi ed and typically displays a large membranous area around the medial distal surface of the syncoxa, facilitating fl exure of the distal part of the maxilla.Th is prehensile type is found in all other ectinosomatid genera, including Chaulionyx, gen.n.Within this group (and the entire family) only three genera -in addition to Chaulionyx -display a prehensile P1 endopod: Halophytophilus Brian, 1919, Bradyellopsis Brian, 1925and Klieosoma Hicks & Schriever 1985.Among this group, the primitive genus Klieosoma can be readily distinguished by the ancestral 3-segmented condition of the P1 endopod, bearing 4 (K.spinosa Hicks & Schriever, 1983) or 5 elements (K.triarticulatus (Klie, 1949)) on the distal segment, unlike the 2-segmented condition consistently reported for the other three genera.Chaulionyx diff ers from the remaining two genera in the presence of a conspicuous bifi d claw (in addition to 5 well developed plumose setae) on the distal endopod segment of P1, the presence of distinctive subrectangular middorsal pores on the urosomites (similar pores have thus far only been reported for Ectinosoma; cf.Huys and Bodin 1997) and the unarmed sixth legs in the male (in both Bradyellopsis and Halophytophilus the male P6 bears 1 seta).Descriptions of all species of Bradyellopsis (except B. foliatus Watkins, 1987) are incomplete (Wells 2007) but diff er from C. paivacarvalhoi in the presence of a large spine (or spinous process) on segment 2 (and often segments 1 and 3) of the antennule, the rudimentary antennary exopod (at most a small segment with 1-3 setae), the spinous projections on the caudal rami and the detailed morphology of P1 enp-2.Species belonging to Halophytophilus can be distinguished from C. paivacarvalhoi by the presence of 3 outer spines on P1-P4 exp-3 but only 3 elements on P1 enp-2.
On the distinction between Noodtiella and Lineosoma Wells (1965) proposed two new genera for interstitial ectinosomatids from the Canary Islands and Portugal, and England, respectively: Noodtiella Wells, 1965 (type species by original designation: Sigmatidium ?arenosetelloides Noodt, 1958) and Lineosoma Wells, 1965 (type species by original designation: Lineosoma iscense Wells, 1965; since the gender of the genus is neuter the incorrect original spelling iscensis is amended here accordingly, cf.ICZN Art.30.1.2).Both Noodtiella Wells, 1965 andNoodtia Lang, 1965 have the same name-bearing type, S. ?arenosetelloides Noodt, 1958, and are therefore objective synonyms.Th e former takes precedence over the latter [see postscript in Lang (1965: 547)].Wells (1965) remarked on the close similarity between Noodtiella and Lineosoma (e.g. in body shape, antennule, antenna, prehensile maxilla, P5) but considered the 2-segmented condition of the P1-P4 endopods in the former (as opposed to 3-segmented in Lineosoma) suffi cient justifi cation for the separation into two genera.
Wells' (1967) description of N. intermedia rendered the distinction between Noodtiella and Lineosoma no longer tenable since his species displayed a 2-segmented P1 endopod but 3-segmented P2-P4 endopods.According to the author the segmentation pattern in N. intermedia can so readily be interpreted as intermediate between the two known conditions that, collectively, the species included in Noodtiella and Lineosoma form an evolutionary sequence.Consequently, Wells (1967) synonymised both genera, stating that Noodtiella Wells, 1965 (p. 30) has page priority over Lineosoma Wells, 1965 (p. 33) and the latter must sink as a junior subjective synonym of the former.Th is course of action was followed by Lindgren (1975) who added N. enertha (another species with 3-segmented P1-P4 endopods) to the genus.
b Lindgren (1975) claimed this species is unique by the presence of two inner setae on P2-P4 enp-1; this is undoubtedly an observational error resulting from misinterpreting the setular tuft for a supernumerary seta.In addition, the author stated correctly that P2-P4 enp-2 has 6 setae but this is not refl ected in his setal formula which gives 221 for these segments.Finally, his illustration of P1 showing no seta on enp-2 but a 221 armature pattern on enp-3 requires confi rmation since it confl icts with the pattern observed in N. iscensis (a 1.1.121formula for P1 endopod would be more likely).
c Wells (1967) showed an outer distal spine on P1 enp-2 but this is likely to be the distal portion of the artifi cially displaced inner seta.Wells and Rao (1987) pointed out that the original description is wrong in that P1 enp-2 bears four elements, not three.
d Mitwally and Montagna (2001) list the formula for P2-P4 enp-2 as 221 but do not take into account the posterior surface seta; the formula is here amended to 321 e Wells and Rao's (1987) illustration of the P2 is likely to be incorrect; the distal endopod segment appears to be reversed although the spinule row marking the original subdivision is illustrated on the correct (outer) margin; given the close relationship to N. pectinata it is also conceivable that the authors overlooked the posterior surface seta on P2-P4 enp-2.
f Th e armature formula of P1 enp-2 is 121 according to Wells' (1965) Table I but the illustration of this appendage (his Fig. 9) shows 120 instead.Similarly, it appears that the P2 exopod is rotated 180 degrees in his Fig. 10 giving the false impression that there is no inner seta on enp-1.
g Rouch (1962) lists the posterior surface seta of enp-2 for P3-P4 in his setal formula (and fi gures it for the P4) but not for P2; this loss requires confi rmation and should not be used as a character to diff erentiate N. problematica from N. pacifi ca.Mielke (1987b) also used the absence of the inner seta on P4 exp-1 in N. problematica as an additional diff erence but this seta is reduced in N. pacifi ca and may well have been overlooked in Rouch' (1962) original description.It is conceivable that N. pacifi ca and N. problematica are conspecifi c.
2-segmented P4 exopod -once again casts doubt on the validity of this generic distinction, and Mielke (1987a) pointed out that Lineosoma in Kunz's (1975) sense was not diagnosed by an autapomorphy.Th is eff ectively renders the genus a paraphyletic group with respect to the species currently included in Noodtiella.Consequently, Lineosoma is here relegated to a junior subjective synonym of Noodtiella, adopting Wells' (1967) argument of page priority.Chappuis (1954a) described two new species of Arenosetella, A. incerta (P1-P4 with 3-segmented endopods) and A. pectinata (P1-P4 with 2-segmented endopods) and presented illustrations of a fi fth copepodid stage which he named "Arenosetella spec.juv.".Th ese three forms co-occurred in the intertidal zone of Canet-Plage, which -in the absence of any habitus drawings in Chappuis' descriptions -made Lang (1965) suggest that "Arenosetella spec.juv." and A. pectinata represented the fourth and fi fth copepodids of A. incerta, respectively.Conversely, Noodt (1958) surmised that Arenosetella pectinata Chappuis, 1954a was a valid species that may be assigned to the genus Ectinosomoides.Bodin (1997) listed the new combination Ectinosomoides pectinatus (Chappuis, 1954a) as a species incerta but incorrectly stated that Lang (1965) agreed with Noodt's (1958) opinion.Wells (2007) eff ectively listed A. pectinata as a synonym of A. incerta, claiming that the juvenile status of the former is corroborated by the diff erent lines of circumstantial evidence highlighted by Lang (1965) (smaller body size, 2-segmented P2-P4 endopods with vestigial segment boundaries between enp-2 and enp-3) and Wells and Rao (1987) (juvenile condition of anal ornamentation).Copepodid V stages of Arenosetella lack the pseudoperculum and prominent anal hooks expressed in the adults but possess instead an arcuate anal operculum which bears a series of spinular extensions (Noodt 1952;Lang 1965;Wells and Rao 1987).Th is condition is also found in "Arenosetella spec.juv." and appears to reinforce Chappuis ' (1954a) claim that this stage represents the last copepodid of A. incerta, however, it is radically diff erent from that displayed in A. pectinata.Chappuis (1954a), in his description of the latter, stated "…, à la place de l'opercule anal, deux plaques symétriques se terminant chacune en 5 à 6 pointes".A similar raised pair of multidentate lamellae on the anal somite was described for two closely related species in the genus Noodtiella: N. ornamentalis Wells &Rao, 1987 andN. toukae Mitwally &Montagna, 2001.Based on this character and the apparent differences with Arenosetella, Wells and Rao (1987) suggested that N. ornamentalis may be placed in a genus separate from Noodtiella but refrained from formally naming and diagnosing it.However, N. ornamentalis displays all the diagnostic characters of Noodtiella and has exactly the same swimming leg setal formula as N. wellsi Apostolov, 1974, which lacks the multidentate lamellae (Table 2).Since removing this species, and the closely related N. pectinata/N.toukae, would render Noodtiella a paraphyletic taxon, they are here retained in the genus as representatives of a specialized lineage characterized by the conspicuous anal ornamentation.Mitwally and Montagna (2001) compared N. toukae with N. ornamentalis but naturally not with A. pectinata.Comparison with Chappuis' (1954a) description reveals complete congruence in the morphology of the swimming legs, fi fth legs of both sexes and the anal somite between both Mediterranean forms.Consequently, A. pectinata is here removed from its uncertain position in Ectino-somoides to the genus Noodtiella as N. pectinata comb.n., and N. toukae is relegated to a junior subjective synonym of the latter.
A dichotomous key to the 18 valid species of Noodtiella is presented below.Swimming leg setal formulae for these species are compiled in Table 2

Key to the Genera of Ectinosomatidae
Th e genus Tetanopsis Brady, 1910 (type species: T. typicus) is included in the key below based on its allegedly 1-segmented antennary exopod, however, it should be recognized that its status is currently doubtful (Huys et al. 1996;Wells 2007) as well as the grounds for subsequently allocating T. medius Perkins, 1956, T. smithi Perkins, 1956 and Arenosetella mediterranea Chappuis, 1954b to this genus (Perkins 1956;Lang 1965).Th e antennary exopod of Ectinosomoides was claimed to be entirely absent (Nicholls 1945) and this character was adopted by Wells (2007: 381) in his tabular keys.Huys et al. (1996: 158) scored the exopod as 3-segmented in their dichotomous key and this condition has been confi rmed by re-examination of the single female of E. longipes Nicholls, 1945 found among the type material of Neoleptastacus spinicaudatus Nicholls, 1945(cf. Sak et al. 2008: 435).Nicholls (1935) established the genus Hastigerella for a new species Hastigerella palpilabra Nicholls, 1935 but McLachlan andMoore (1978: 198) relegated it to a junior synonym of Ectinosoma tenuissima Klie, 1929 and -based on their assertion that Nicholls (1935) had overlooked the anal claws -transferred this species to Arenosetella.Th ey retained Hastigerella as a valid generic name and illegitimately designated Ectinosoma leptoderma Klie, 1929 as the new type species (ICZN Art.61.1.3).Huys (2009) pointed out that adopting McLachlan and Moore's (1978) synonymy of H. palpilabra would render Hastigerella a junior subjective synonym of Arenosetella and therefore an invalid name.He proposed a new name, Glabrotelson (type species: Hastigerella mehuinensis Mielke, 1986), for the orphaned taxonomic grouping equivalent to Hastigerella sensu McLachlan and Moore (1978).Seifried et al.'s (2007) course of action to upgrade the subgenus Bradya (Parabradya) to full generic rank appears premature since this leaves Bradya (now equivalent to its nominotypical subgenus) with only one questionable autapomorphy and hence a potentially paraphyletic status.Th e authors considered the maxillipedal endopod being fused to the basis at an angle as suffi cient evidence to warrant separate generic status for the nominotypical subgenus Bradya.However, as the authors admitted themselves the fusion is not complete in some as yet undescribed Bradya species.Both Bradya and Parabradya are retained here as valid genera but an in-depth study of all species accommodated in the former genus is required before the validity of this separation can be confi rmed.Lang (1936) showed 5 setae on the exopodal lobe of the female P5 in Parabradya confl uens (Lang, 1936).Th is is a very unusual condition not found in any other extant member of the Ectinosomatidae (see also Seifried et al. 2007) and would require re-examination of the type material before it can be used for identifi cation.
As has been pointed out by Karanovic and Pesce (2001), Vervoort (1962: 399) explicitly fi xed Ectinosoma sarsii Boeck, 1873 as type species of the subgenus Ectinosoma (Halectinosoma) but Lang (1965: 11), who upgraded Halectinosoma to generic status, did not mention Vervoort's (1962) designation.A comparison of the diagnoses of the two subgenera given in Lang (1944: 6) shows that Halectinosoma is distinguished from Ectinosoma on the basis of the setation of the exopod of leg 5. Th erefore, the generic name Halectinosoma is available from Vervoort (1962), who cited (p.255) that page in Lang (1944) in this connection and designated a type species (Huys 2008(Huys , 2009)).Wells and Rao (1987) placed their new species Halophytophilus aberrans with some diffi dence in the genus Halophytophilus because it showed signifi cant diff erences with its congeners in the non-prehensile P1 endopod and the armature of the P2-P4 endopods, in addition to discrepancies in the accessory ornamentation of the swimming legs and abdomen, and in the P5 and the caudal rami.Th e authors believed that there was a case for proposing a new subgenus for this species while Huys et al. (1996) surmised that it may belong to a separate genus.Bodin (1997) and Wells (2007) placed H. aberrans in the genus Klieosoma without giving any factual justifi cation for this course of action.Gheerardyn et al. (2008) did not consider the species in their review of the genus Halophytophilus.It has now come to our attention that Wells and Rao's (1987) setal formula of P4 contradicts their illustration.In their description the authors stated that P2-P4 exp-1 lacks an inner seta while their Fig.28f clearly shows a well developed seta on this segment in leg 4. Huys et al. (1996) constructed their generic key on the assumption that this seta was absent in all swimming legs and hence H. aberrans may have keyed out to the wrong couplet.Without any illustrations of the maxilla (although Wells and Rao did state that the mouthparts were as in H. simplex Wells & Rao, 1987) and P2-P4 it is impossible to decide which genus H. aberrans belongs to and, consequently, it is here considered species incertae sedis in the Ectinosomatidae.A dichotomous key to the 21 valid genera in the Ectinosomatidae is given below.
of which exhibit a Table2.Swimming leg armature formulae of the 18 valid Noodtiella species (P4-OS = outer spine of P4 exp-2 present/absent; P5-OS♀ = outer endopodal spine fused to baseoendopod in female/discrete at base).Segments with numerals in boldface refer to endopodal segments with posterior surface setae.

Table 1 .
Coordinates and environmental parameters of sampling sites where Chaulionyx paivacarvalhoi gen.et sp.n. was recorded during the interdisciplinary project "Utilização Racional do Ecossistema Costeiro da Região Tropical Brasileira: Estado de São Paulo" (Departamento de Oceanografi a Biológica -IOUSP).Stations were sampled across the inner continental shelf of São Paulo State between São Sebastião