Corresponding author: Charles Oliver Coleman (
Academic editor: Carsten Lüter
The poorly known species
Participants in a workshop organised by Professor Wim Vader at the University of Tromsø field station at Skibotn in 2009 sorted and identified amphipods from the Natural History Collections of the University Museum of Bergen collected from the Norwegian Sea. Among the extensive material in these collections were specimens of the poorly known oedicerotid genus
The new material from the Bergen Museum has made possible a re-description of
This paper is the third to utilize material sorted at Skibotn in 2009, following
Norwegian Sea material assigned to
Specimens from the Discovery Collections at the National Oceanography Centre, Southampton were obtained in the East Iceland Basin on an RRS
The New Zealand material was collected during the Ocean Survey 2020 expeditions with RV
For habitus drawings the specimens were transferred into glycerol on a cavity slide. Specimens were then dissected under a stereomicroscope (Leica M205 or Wild M5) using dissecting needles. Mouthparts and appendages were mounted temporarily in glycerol on slides for microscopic examination and drawing. Appendages were later mounted as permanent slides with glycerol jelly, or transferred into small glass microvials. Microvials were stoppered with a cotton ball wrapped in Japan paper to avoid the appendages being entangled in the cotton fibres.
After dissection, mouthparts and appendages of Discovery Collection material were made directly into permanent mounts using Polyvinyl-lactophenol stained with lignin-pink. Drawings of habitus and appendages were made using a
Body lengths were measured along the dorsal outline from the tip of the rostrum to the end of the telson. Lengths of individual articles of gnathopods and pereopods measured along anterior or posterior margins can vary depending on the degree of flexure of the appendage. All articulations except those between coxae and tergites and between merus and carpus of gnathopods are bicondylar. Measurements made between condyles gives a length that is not affected by limb flexure. Length ratios herein have been derived using this principle.
Rostrum well-developed, moderately to strongly deflexed. Antennae sexually dimorphic or not, length medium. Antenna 1 about as long as head and pereonites 1–4 combined, peduncle article 1 longer than articles 2 and 3. Antenna 2 subequal to or weakly longer than antenna 1; peduncle article 4 longer than article 5. Lower lip, inner lobes prominent, separate. Mandible, molar triturative; incisor 5-dentate. Maxilla 1, outer fig 9-dentate; palp slender, article 2 subequal to or longer than article 1. Maxilla 2, figs short, inner broader than outer. Maxilliped, palp article 2 sub-triangular, breadth greatest at half-length, inner margin strongly convex; article 3 produced mediodistally; article 4 longer than article 3.
Coxal figs 1–4 deep, as long or longer than height of corresponding pereonite.
Pleonites, some or all carinate or toothed. Epimera 1–3, 1 and 3 rounded, 2 obtusely rounded, posterior margin convex or sinuous. Uropods 1–2, outer ramus subequal to or shorter than inner ramus. Uropod 3, peduncle short; rami subequal, not extending as far as apices of uropods 1–2. Telson notched 30–40%, apices acute.
1 | Rostrum massive, spatulate, longer than peduncle article 1 of antenna 1 | |
– | Rostrum at most as long as article 1 of antenna 1 | 2 |
2 | Pleonites 1–2 carinate, pleonite 3 with small tooth | |
– | Some pleonites smooth dorsally | 3 |
3 | Pleonite 1 smooth | 4 |
– | Pleonite 1–2 carinate, pleonite 3 smooth | |
4 | Pleonite 1–2 smooth | |
– | Pleonite 2 carinate, pleonite 3 with short process |
3 ovig. females, 6 females, 3 males, 2 unknown sex, 4 juveniles, ZMBN 95143, St. 81.08.14.5,
1 female, 1 male, 1 juvenile, ZMBN 95144, St. 81.08.14.1,
1 ovig. female, 4 females, 7 males, 3 unknown sex, 12 juveniles, ZMBN 95145, St. 82.11.24.1
1 male, 1 juvenile, ZMBN 95146, St. 81.06.03.5,
1 female, ZMBN 95147, St. 86.07.26.1,
2 adult females, 1 female, 2 juveniles, NORBI St. 2, DS05,
1 ovig. female, 1 adult male, NORBI St. 6, DS12,
Based on ovigerous female, 10.3 mm, St. 81.08.14.5.
Male antenna 1 with shorter peduncle articles in the ratio 1:0.7:0.3 and more numerous flagellum articles compared to female. Article 1 of the flagellum is elongate, about as long as peduncle article 3. Subsequent proximal articles are shorter than wide. The 1-articulate slender accessory flagellum is about 1/3 as long as article 1 of the primary flagellum.
Between the Faroes and Jan Mayen (
Male holotype, 7.3 mm; NHMUK 2014. 398, Discovery Stn 7709#73.
North Atlantic, East Iceland Basin:
1 female, 6.3 mm; 2 specimens of unknown sex, 4.2 mm and 5 mm; NHMUK 2014. 399-401, Discovery Stn 7709#73, from the type locality.
The specific name
Holotype male, 7.3 mm.
The paratypes bear a small posteriorly directed tooth on pleonite 3. It may be that this process has been present and is worn down in the holotype. Antenna 1 of the female (Fig.
North Atlantic, south of Iceland, 2636–2646 m.
Male, 8.5 mm; NIWA 84727, TAN 0705-41, Chatham Rise,
The species is named for Dr. Anne-Nina Lörz to acknowledge her significant contributions to amphipod systematics.
Holotype male, 8.5 mm.
Chatham Rise, east of New Zealand.
The female specimen has the same antenna 1 morphology as the male: short peduncle articles and numerous flagellum articles. The proximal articles of the flagellum are shorter than wide.
1 incomplete female; NHMUK 2014. 402, Discovery Stn 7845: north-eastern Atlantic, off the coast of Western Sahara:
Only the head and pereonites 1–2 are present. Coxae 1–2 bear long setae along the distal margins. The animal appears similar to
The three species described herein are morphologically very similar. Mouthparts and appendages show only minor and subtle differences and the species are best discriminated by habitus characters. Two of the species,
Apart from the type species
The mouthparts and appendages of all species of this genus are remarkably similar to each other. Examination of the extensive Norwegian Sea material which we attribute to
Because of minimal differences among appendages and mouthparts in
We are very grateful to Wim Vader for inviting us to the highly successful identification workshop at Skibotn which provided the material that stimulated the present paper. We acknowledge with thanks Mr. Jon Anders Kongsrud (University of Bergen), Dr Lars Lunqvist (Museum of Zoology, Lund University) and Ms Sadie Mills (National Institute of Water and Atmosphere Research, Wellington, New Zealand) for the loan of material. We thank Ms Camilla Norrag, who drew the appendages of