Corresponding author: Kim Larsen (
Academic editor: M. Blazewicz-Paszkowycz
Three new species of are described from the manganese nodule province between the Clarion and the Clipperton Fracture Zone of the equatorial North Pacific Ocean, and collected during the Nodinaut expedition on board the r/v
The aim of this paper is to present the first part of the taxonomic results from a survey of the Central Pacific Manganese Nodule Province between the Clarion and the Clipperton Fracture Zone of the equatorial North Pacific Ocean. This region has, due to the rich manganese deposits, been a tempting area for mineral exploration. This fact has made the area one of the best surveyed deep-sea regions in the Pacific. For the
The phylogeny and systematics of the
Any collection in remote deep-sea habitats will reveal a significant proportion of undescribed species relative to known species (
Samples were taken during the Nodinaut expedition (17 May – 28 June 2004) from on board of the research vessel
Dissections were made in glycerine using chemically sharpened tungsten wire needles. Body length was measured from the tip of the cephalothorax to the apex of the pleotelson. The terminology in the descriptions is based on
(Modified after
Male. Similar to female. Functional mouthparts retained in adult. Antennule thicker than in female. Pleopods present, most often with simple setae.
Feminine.
Holotype male (MNHN-Ta1029) SUB-CStation MAC 3 #43, 07/06–2004, 13°42.3490'N, 131°29.9940'W, depth > 4000 m.
Body 19 times longer than broad. Antenna article 4 without fusion line. Maxilliped endite with small inner process. Cheliped propodus with setulose inner ridge; fixed finger with multiple prominent sharply pointed processes. Cheliped dactylus not longer than fixed finger. Heavy armament with spiniform setae on all pereopods. Pleopods uniramous and strongly elongated; endopod with four long (longer than antennule) plumose setae. Uropods long (0.3 times pleotelson length), endopod biarticulated.
Named to reflect the long setae of the pleopods.
Adult male, 2.9 mm (body and appendages of holotype).
It is hard to compare
A similar armament of the cheliped fixed finger with its strong inner serration and transverse row of inner setae/setules is also seen in
Manca II SUB-CStation SUB-C # 1, 05/06–2004, 14°01.7913'N, 130°08.1755'W, depth 4987 m.
Manca II
As this species was only recorded from one specimen of stage manca II it is not justifiable to erect a new species. The short uropods indicate however that it is not conspecific with
See
Feminine.
The genus
The mouthparts of this genus are remarkably small relative to the size of the whole animal. When compared to a specimen of the genus
Female. Pereonites 2–4 longer than wide. Pleotelson longer than combined length of four pleonites. Antenna with six articles (+ fusion line), article 4 longer than other articles, with clear fusion line. Cheliped propodus with large paired dorsal tubercles near dactylus insertion. Pereopod 1 merus and carpus with long (longer than length of merus) robust setae.
Male. Unknown.
The species is named after the diagnostic character of the tubercles on the cheliped propodus.
Female(body and appendages of holotype).
1 | Pleotelson longer than last three pleonites | 2 |
– | Pleotelson shorter than last three pleonites | 4 |
2 | Pereonites of subequal length and width. Antenna article 4 without fusion line |
|
– | Pereonite 2 longer than other pereonites. Antenna article 4 with clear fusion line | 3 |
3 | Cheliped propodus with paired dorsal crest next to dactylus insertion |
|
– | Cheliped propodus without paired dorsal crest next to dactylus insertion |
|
4 | Antenna article 4 with clear fusion line. Uropodal exopod almost reaching the end of first endopod article |
|
– | Antenna article 4 without fusion line. Uropodal exopod barely reaching beyond midlenght of first endopod article |
|
(Modified after
Male:Similar to female, but antennule articles 1–3 much wider than in female.
Feminine.
The genus
The labial medial processes or ´lobes´
Manca II. Carapace longer than the lengths of pereonites 1 and 2 combined. Pereonites 2–5 longer than wide. Pleotelson longer than combined length of three pleonites. Mandibular molar tapering. Maxillipedal endites with medial setae. Cheliped propodus and proximal part of fixed finger with calcified keel; fixed finger with clear tubercle distal from the keel; dactylus with dorsoproximal seta. Pereopods 1–3 propodus setae only reaching unguis insertion. Uropods as long as pleotelson.
Male. Unknown.
Named after the Pacific Ocean.
Manca II (body and appendages of holotype).
Bacause the studied specimen represent manca stageit is difficult to compare it with the other species of the genus. The carapace being longer than combined length of pereonites 1 and 2 and the weak armament of the pereopods (particularly the carpus) differentiate
The species
Thanks are extended to Dr. Joëlle Galéron (Ifremer), chief scientist of the Nodinaut expedition and to three anonymous reviewers for improving the quality of this paper.