Marbefia, gen. n.

urn:lsid:zoobank.org:act: 5B070367-A759-44B2-931C-7D9A49AC6AC4

Diagnosis. Laophontidae . Body linear, not dorsoventrally depressed. Integument of cephalothorax and body somites covered with tiny spinules; posterior margins of somites smooth, with spinule rows dorsally and ventrally. Rostrum delimited at base; broadly triangular, prominent. Genital double-somite ♀ with lateral incisions and ventrolateral internal chitinous ribs marking original segmentation. Pleural extensions of ♀ abdominal somites well developed. Caudal ramus cylindrical, subrectangular and as long as wide; inner margin with long spinules; with 7 setae; setae IV and V well developed, pinnate; seta VI reduced, setiform. Anal operculum spinulose.

Sexual dimorphism in antennule, P3–P4 endopods, P5, P6 and in genital segmentation.

Antennule slender and 7-segmented in ♀; 8-segmented and subchirocer with 3 segments distal to geniculation in ♁; segments with spinular ornamentation along anterior margin of segments 1–4 in ♀ and 1–3 in ♁; segments 1–2 without processes; with aesthetasc on segment 4 (♀) or 5 (♁); acrothek on apical segment consisting of 2 setae and one aesthetasc. Antenna with 4 setae on exopod; allobasis with abexopodal seta. Mandibular palp elongate, 1-segmented; with one basal, one exopodal and 3 endopodal setae. Maxillule with defined exopod bearing 2 setae. Maxilla with 3 endites on syncoxa; endopod represented by 4 setae. Maxilliped elongate; syncoxa with 2 setae; basis without distinct ornamentation; endopodal claw long and curved, with one accessory seta.

P1 long, with elongate coxa and basis; with 3-segmented exopod, exp-2 1.6 times as long as exp-1, exp-3 with 2 short and 2 geniculate setae; endopod stout, enp-1 without inner seta, enp-2 with minute seta and long minutely denticulate claw. Swimming legs P2–P4 with 3-segmented exopods and 2-segmented endopods. P2–P4 enp-2 swollen, with double row of flimsy setular extensions along outer lateral margin (except for P 4 in ♁); inner seta of P3–P4 enp-1 present in ♀ but absent in ♁. P3 enp-2 produced into straigth spiniform apophysis in ♁ (homologous with outer spine of enp- 2 in ♀). Armature formula of swimming legs 2 to 4 (P2–P4) as follows:

P5 with separate exopod and baseoendopod. Exopod elongate with 6 setae in ♀ and 4 setae in ♁. Endopodal lobe well developed in ♀, subrectangular, with 5 setae. Baseoendopods fused medially in ♁; endopodal lobes rudimentary, with 2 setae each.

P6 forming well developed operculum with 2 small setae in ♀; asymmetrical in ♁ (with dextral or sinistral configuration), with outer distal corner produced into conical process bearing 2 well developed elements.

Type and only species. Pseudonychocamptus carthyi Hamond, 1968 = Marbefia carthyi (Hamond, 1968), comb. n.

Etymology. The name of the new genus honours the advances in our understanding of marine ecosystem functioning stimulated by the MarBEF Network of Excellence in Marine Biodiversity and Ecosystem Functioning. Gender: feminine.