Kirkegaardia jongo, Freitas & Ribeiro & Ruta, 2022

Freitas, Roberta, Ribeiro, Rannyele Passos & Ruta, Christine, 2022, Kirkegaardia Blake, 2016 (Annelida: Cirratulidae) from Southeastern Brazil with description of nine new species, PLoS ONE (e 0265336) 2016 (5), pp. 1-27 : 12-15

Kirkegaardia jongo sp. nov.

urn:lsid:zoobank.org:act:5516ACDD-13DE-482E-88B8-8A1BF6C949E2 .

Fig 7

Material examined. BRAZIL: Campos Basin – Holotype – -20.06893889˚S -38.52425556˚W, 1288 m, 21/12/11, ( MNRJP-002997 ); Paratypes – -20.60056389˚S -39.85982500˚W, 991 m, one ind., 08/01/2012, ( MNRJP-002998 ); -19.82691667˚S -39.59519167˚W, 352 m, one ind., 28/06/ 13, ( MNRJP-002999 ) .

Diagnosis. Presence of a peristomial crest along the peristomium. Peristomium with two or three annulations. Thoracic region without visible crest. Noto and neurosetae denticulated. Presence of a small segment, demarcating the separation of the pre-pygidial region from the other abdominal segments.

Description. Complete holotype with 58 setigers, 2.4 mm long, 0.2 mm wide in thoracic region, and 0.07 mm wide in abdominal region. Prostomium narrow, triangular ( Fig 7A ). Eyes absent. Peristomium with 2–3 rings and dorsal crest ( Fig 7A ). Dorsal tentacles on posterior margin of peristomium ( Fig 7A ). First pair of branchiae postero-lateral to the tentacles on the posterior most border of peristomium; second pair of branchiae in setiger 1 dorsal to notosetae ( Fig 7A ); branchiae continuing to anterior abdominal segments. Thoracic region with nine setigers, slightly expanded; dorsal groove barely visible with optical microscope. Abdominal segments wider than long. Parapodia with poorly developed lobes, difficult to see with optical microscopy. Thoracic parapodia with 4–5 capillary noto- and neurosetae per segment. Posterior abdominal parapodia with 4–6 denticulate noto- and neurosetae ( Fig 7C and 7D ) per segment. Denticulate neurosetae from abdominal setiger 17. Pre-pygidial segments well-defined, marked by the presence of a small narrow segment, separating pre-pygidial region from other abdominal segments ( Fig 7B ). Pygidium small, rounded ventral lobe ( Fig 7B ).

Remarks. The presence of a peristomial crest brings K. jongo sp. nov. as well as K. papaveroi sp. nov. and K. goytaca sp. nov. to the group of four species considered to be from deep sea: K. annulosa , K. cristata , K. kladara and K. hampsoni . Among these species, K. hampsoni and K. jongo sp. nov. do not have a visible crest in the thoracic region. K. annulosa differs from K. jongo sp. nov. by having hooks in addition to modified setae, and pre-pygidial segments ventrally flattened culminating in a conical pygidial lobe. Kirkegaardia jongo sp. nov. has no hooks, and the pre-pygidial segments are fully expanded, culminating in a small rounded pygidial lobe. Kirkegaardia kladara differs from K. jongo sp. nov. by the presence of a thoracic crest and with the first pair of branchiae on setiger 1, whereas in K. jongo sp. nov. the first pair of branchiae are on the posterior margin of the peristomium. Kirkegaardia cristata , differs from K. jongo sp. nov. in having an extremely long prostomium and moniliform segments in the abdominal region while K. jongo sp. nov. has a triangular prostomium, and abdominal segments wider than long. K. cristata also has a thoracic ridge, and K. jongo sp. nov. does not have a thoracic crest. Kirkegaardia hampsoni differs from K. jongo sp. nov. in having a peristomium without rings, while K. jongo sp. nov. has two or three annulations in the peristomium, and by the number of abdominal setae per fascicle, 8–12 in K. hampsoni , and 4–6 in K. jongo sp. nov. For all these differences, the species was considered as new to science.

Etymology. This species is named after the quilombolan dance known as “jongo ”, as a tribute to the African legacy left in the southeastern Rio de Janeiro State, region that comprises a large part of the sampling points where Kirkegaardia jongo has been collected.

Figures

Fig 7. Kirkegaardia jongo sp. nov. (A) anterior end, dorsal view; (B) posterior end, lateral view; (C) denticulated notopodial capillary; (D) denticulated neuropodial capillary. A–B (MNRJP-002997). Scale bars: 100 μm (A and B). Type locality. Atlantic Ocean: Campos Basin (Brazil). Habitat. Fine sediments composed of silt and clay, or sand, depth between 352 to 1288m. Distribution. Presently known only from Atlantic Ocean: Campos Basin (Brazil). Methyl Green. No pattern, stain not retained. https://doi.org/10.1371/journal.pone.0265336.g007