Scalibregmatidae Malmgren, 1867

Blake, James A., 2023, New Species of Scalibregmatidae (Annelida) from Slope and Abyssal Depths off Eastern Australia, Records of the Australian Museum (Rec. Aust. Mus.) 75 (3), pp. 271-298 : 272-273

Family Scalibregmatidae Malmgren, 1867

Type genus: Scalibregma Rathke, 1843 , by monotypy.

Diagnosis (after Blake, 2020): Body variably shaped: (1) elongate and narrow throughout, (2) fusiform, (3) thick, maggot-shaped, or (4) elongate arenicoliform with anterior segments greatly expanded; with no more than 30 to 60 setigerous segments. Body with one to five annular rings on each segment; each ring usually composed of elevated pads; distribution of these rings and pads differs among species; venter with mid-ventral groove or ridge formed of elevated pads along body, limited to one part of body or entirely absent. Prostomium either bilobed or T-shaped with two frontal or lateral horns, sometimes long, ciliated, and functioning as palps; eyes present or absent; nuchal slits present. Proboscis eversible, soft, unarmed. Peristomium with a dorsal ring typically single, encompassing prostomium; ventral part with one to three rings forming upper and lower lips of mouth. Branchiae present or absent, when present limited to four to six or fewer anterior setigers, always with multiple branches, usually dichotomous. Parapodia biramous, with weakly developed podial lobes; interramal sensory organs or papillae present; dorsal and/or ventral cirri present or absent in middle and posterior segments, when present often with internal tubular glands; postsetal lamellae rarely present. Setae all simple, including capillaries, furcate or lyrate setae present or absent, acicular spines on anterior segments present or absent; short spinous setae often present anterior to capillaries on setigers anterior to those where furcate setae begin. Pygidium with two or more lobes; anal cirri present or absent.

Remarks. Scalibregmatids are active burrowers and subsurface deposit feeders that never form tubes. They are readily recognized by their large, often maggot-shaped, bodies that have a rugose or lumpy looking surface and a prostomium typically with frontal horns. The family is composed of 15 genera and c. 72 species ( Blake, 2015, 2020; Read & Fauchald, 2022). In Australia, six named species in five genera ( Asclerocheilus , Axiokebuita , Hyboscolex , Oligobregma , and Pseudoscalibregma ) have been reported (http://www.ala.org.au). In the present study the deep-water samples contained four genera and seven new species ( Asclerocheilus abyssalis sp. nov., Axiokebuita australis sp. nov., Oligobregma aristata sp. nov., Oligobregma bathyala sp. nov., Oligobregma profunda sp. nov., Oligobregma renuncula sp. nov., and Pseudoscalibregma glandipodium sp. nov.).

The following species are included in this article:

Asclerocheilus abyssalis sp. nov.

Axiokebuita australis sp. nov.

Oligobregma aristata sp. nov.

Oligobregma bathyala sp. nov.

Oligobregma profunda sp. nov.

Oligobregma renuncula sp. nov.

Pseudoscalibregma glandipodium sp. nov.