Paranaitis cordiformata

Oliveira, Verônica Maria De, Jacobsen, Danny Eibye & Lana, Paulo, 2018, Four new species of Paranaitis Southern, 1914 (Phyllodocidae, Annelida) from southern and southeastern Brazil, Zootaxa 4444 (2), pp. 120-136: 132-135

publication ID

https://doi.org/10.11646/zootaxa.4444.2.2

publication LSID

lsid:zoobank.org:pub:1A4D6398-EC3A-4279-9846-54EC268CB3D2

persistent identifier

http://treatment.plazi.org/id/137A0A12-FFF3-FFF5-0193-D290A411C09B

treatment provided by

Plazi

scientific name

Paranaitis cordiformata
status

sp. nov.

Paranaitis cordiformata  sp. nov.

Figs 13–14View FIGURE 13View FIGURE 14

Holotype. Margin of continental shelf, Campos Basin, Brazil, Hab 17 I03 R01, 21°23'38.0"S, 40°15'37.1"W, 88 m, well-sorted fine sediment, 21 Jul. 2009 (ZUEC- POL-16342).

Paratype. A total of 7 paratypes, length ranging from 5–20 mm and number of segments ranging from 25– 115. Paranaguá Bay , Paraná, Brazil: Cotinga Channel, 25°30'41.6"S, 48°29'50.3"W, intertidal, 1 Feb. 2011 (1 paratype, NHMD-207973); Maciel shoal, 25°33'23"S, 48°24'58"W, 13 Apr. 2010 (1 paratype, ZUEC-POL-16489); Papagaios shoal, 25°32'56"S, 48°26'08"W, Jun. 2011 (1 paratype, ZUEC-POL-16564)GoogleMaps  . Paranaguá Bay , 25°30'41.6"S, 48°29'50.3"W, Sep. 2011, intertidal (2 paratypes, NHMD-207984)GoogleMaps  ; Itiberê River , 25°30'41.6"S, 48°29'50.3"W, Aug. 2011 (1 paraatype ZUEC-POL-16570). Margin of continental shelf, Campos Basin, Brazil: Hab 11 D2 R03, 22°12'53.4"S, 40°51'12.4"W, 52 m, 26 Feb. 2009 (1 paratype, ZUEC-POL-16367). Occurs in wellsorted fine sediment up to 52 m.GoogleMaps 

Diagnosis. Dorsal cirri cordiform and asymmetrical. Chaetae with main tooth conical and short, from segment 2. Pair of cylindrical anal cirri with wide base and tapered distal ends. Rostrum of chaetal shaft with large, conical main fang surrounded by cylindrical denticles of unequal lengths.

Description. Holotype complete with 97 segments, 15 mm long, 1.0 mm wide at the median part of body, including parapodia and excluding chaetae. Body long, dorso-ventrally flattened, with uniform width, except for small tapering region at posterior end. Prostomium triangular, wider than long, anteriorly rounded, with one short nuchal papilla ligule in a distinct depression, in its posterior portion, where rounded nuchal papilla lies ( Fig. 13A– B View Figure ). Paired frontal antennae and palps antero-laterally on prostomium, conical and robust, antennae and palps of equal size, long with tapered distal ends. One pair of subepidermal brown eyes with lenses. Proboscis not everted, not observed. First and second segments dorsally fused to form a collar. Four pairs of cylindrical tentacular cirri, biarticulate, with short cirrophores and long and cylindrical cirrostyles, gradually tapered at distal end, situated on first three segments. Cirri of segment 1 reaching segment 4. Dorsal and ventral cirri of segment 2 reaching segments 5 and 4, respectively. Dorsal cirri of segment 3 reaching segment 11 ( Fig. 13A–B View Figure ). Aciculae not observed in segment 2. Neuropodia and ventral cirri from segment 3. Dorsal cirri with symmetrical cirrophores, developed, without dorsal extension, from segment 4, cordiform and symmetrical. Dorsal cirri on anterior segments distally tapered, on medium segments with more rounded tips, and on posterior segments almost as long as wide ( Fig. 13D–E View Figure ). Parapodial lobes shorter than dorsal and ventral cirri, with clear aciculae and bundles of chaetae. Prechaetal lobes bilobate, asymmetrical and rounded, supraacicular lobes clearly wide than subacicular lobes. Ventral cirri horizontally oriented in relation to lobes, asymmetrical, on anterior segments oval and distally rounded, on medium segments oval and distally rounded, but with weak tip pointing downwards, and on posterior segments oval, more slender and more symmetrical ( Fig. 13A–C View Figure ). Compound spinigerous chaetae from segment 2 ( Fig. 13C View Figure ). Rostrum of chaetal shaft with large, conical main fang surrounded by cylindrical denticles of unequal lengths, articles with serrated outer edges ( Fig. 14A–C View Figure ). Pygidium with one pair of cylindrical anal cirri with wide base and tapered distal ends. Median pygidial papilla absent ( Fig. 14D View Figure ).

Coloration. Preserved specimens are opaque.

Distribution. Atlantic Ocean, Brazilian continental margin; areas of the continental shelf in the Campos Basin. Paranaguá Bay, Paraná—Brazil.

Etymology. The species name comes from the Latin word cordis and refers to the shape of the dorsal cirri.

Remarks. The cordate shape of the dorsal cirri in Paranaitis cordiformata  sp. nov. is similar to those in P. wahlbergi  and P. gardineri  ; on the other hand, they are completely different from the rounded and reniform dorsal cirri described in P. bowersi  , P. caeca  , P. gardineri  , P. moritai  , P. uschakovi  and P. wahlbergi  . This species is similar to P. speciosa  by the presence of nuchal papilla and primary chaetal teeth ( Kato & Pleijel, 2003); however, it differs in the shape of dorsal and anal cirri, which are more rounded in P. speciosa  . Paranaitis cordiformata  sp. nov. shares the anal cirri morphology with P. gardineri  but it differs by the absence of a median pygidial papilla and the cylindrical shape of the anal cirri. Paranaitis cordiformata  sp. nov. differs from P. cirriformata  sp. nov., P. assimetrica  sp. nov., P. bowersi  , P. caeca  , P. inflata  , P. gardineri  , P. kosteriensis  , P. misakiensis  , P. polynoides  , P. pumila  , P. speciosa  , and P. uschakovi  in lacking a pygidial papilla. The cylindrical anal cirri with inflated bases are shared with P. caeca  , P. gardineri  , and P. polynoides  . Paranaitis cordiformata  sp. nov. shares the presence of neuropodial chaetae in the second segment with P. benthicola  and P. moritai  . However, it differs from P. chitinosa  sp. nov., P. assimetrica  sp. nov., P. caeca  , P. misakiensis  , P. polynoides  , and P. pumila  , in which neuropodial aciculae are present in the segment 2.