Diacyclops eberhardi Karanovic 2024, sp. nov.
Creators: name: Karanovic, Tomislav
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Copepoda
Cyclopoida
Cyclopidae
Diacyclops
Diacyclops eberhardi

description: Diacyclops eberhardi sp. nov.
(Figs. 1B, 8–12)
urn:lsid:zoobank.org:act: 66BA5A5F-161F-46F8-B638-614CC67D06CB
Type locality. Western Australia, Margaret River, Easter Cave, 34.274367°S 115.099297°E, 12 March 2002, collected by S. Eberhard.
Holotype. Adult female dissected on 1 microscope slide.
Paratypes. One male from type locality dissected on 1 microscope slide; 2 males and 2 females from type locality on 1 SEM stub (row no. 5), together with 5 other species described here; 3 males and 11 copepodids from type locality in 1 alcohol vial; 3 males in 1 alcohol vial from Jewel Cave, Margaret River, Western Australia, 34.2738°S 115.098413°E, 6 March 2002, collected by S. Eberhard.
Etymology. The species is named after Dr. Stefan M. Eberhard, University of New South Wales, Sydney, who collected this species and entrusted it to me for identification. The name is a noun in the genitive singular.
Diagnosis. Female. Body length from 360 to 470 µm. Habitus (Figs. 1B, 11A) spindle-shaped, about 2.5 times as long as wide, with prosome/urosome ratio of nearly 1.5, and posterior end of cephalothorax about 2.3 times as wide as genital double-somite in dorsal view. Integument on all somites (Fig. 11B, C, D, E) thin and smooth, with light bacterial cover; general distribution of spinules and cuticular pores on somites as in D. leijsi, but their number differs and differences in distribution prevent homologisation (especially on cephalothorax). Hyaline fringes of prosomites (Fig. 11C) and first urosomite (Fig. 11D) smooth, those of genital double-somite and 2 subsequent urosomites (Fig. 11E) slightly wavy. Genital double-somite (Fig. 8A) slightly wider than long in ventral view, widest at first fifth of its length and gradually tapering posteriorly, widest part about 1.5 times as wide as posterior margin; seminal receptacle large and shaped like a young mushroom; copulatory pore large; copulatory duct wide, long, and well-sclerotized. Anal somite (Figs. 8A, 11E) with large spinules along ventral margin. Caudal rami (Figs. 8A, 11F) stubby, spaced about a half or ramus’ width, nearly 3 times as long as wide and about twice as long as anal somite; principal terminal setae with breaking planes, inner one about 1.3 times as long as entire urosome and 1.75 times as long as outer one; dorsal seta about 1.5 times as long as caudal ramus, 2.2 times as long as innermost terminal seta, and nearly 2.5 times as long as outermost terminal seta. Antennula (Fig. 8B) 12-segmented, slightly shorter than cephalothorax, with 1 aesthetasc on ninth and eleventh segments each and setae formula 8.4.2.6.2.2.2.3.2.2.2.8; ultimate segment about 1.6 times as long as wide. Antenna (Fig. 8C) 5-segmented, without exopodal seta, with setae formula 0.2.1.6.7; second segment nearly 1.3 times as long as fifth segment. Labrum, mandibula (Fig. 8D), maxillula (Fig. 8E), maxilla (Fig. 8F), and maxilliped as in D. leijsi. Segmentation of all swimming legs (Fig. 9A, B, C, D, E) as in D. leijsi, but they are all wider, and especially endopod of fourth leg; basis of first leg with long outer seta and short inner spine, latter slightly longer that first endopodal segment; basis of second to fourth legs with shorter outer seta and inner distal corner blunt; all first exopodal segments without inner seta; all second exopodal segments, all first endopodal segments, and second endopodal segment of first to third legs with single inner seta; second endopodal segment of fourth leg with 2 inner setae; third exopodal segments spine formula 2.3.3.3 and setae formula 4.4.4.4; third endopodal segments of first to third leg with 2 inner setae, 1 apical seta, 1 apical spine, and 1 outer seta; third endopodal segment of fourth leg 1.36 times as long as wide, with 2 inner setae, 2 apical spines, and 1 outer seta; its outer spine nearly 1.4 times as long as segment and twice as long as inner spine. Fifth leg (Figs. 8A, 9F) shape and segmentation as in D. leijsi; second segment about 1.8 times as long as wide and slightly shorter than its spine. Sixth leg (Fig. 9G) narrower than in D. leijsi, but with little difference in armature; seta slightly longer than plate width.
Male. Body length from 360 to 450 µm. Habitus (Fig. 12A) and urosome (Fig. 10A) slightly slenderer than in female; free genital somite (Fig. 10A) about 1.6 times as wide as subsequent urosomite, with relatively large ovoid spermatophores. Ornamentation of cephalothorax (Fig. 12B), free prosomites (Fig. 12C), and urosomites (Figs. 10A, 12A, D) as in female. Anal somite (Figs. 10A, 12A) shorter than in female and with smaller ventral spinules. Caudal rami (Figs. 10A, 12A) slightly slenderer than in female, with shorter dorsal seta. Antennula (Figs. 10B, 12E) very similar to that in D. leijsi, but shorter, fourth and fifth segments fused on anterior surface, and ninth segment almost completely fused with eighth; armature and ornamentation of first 3 and last 7 segments as in D. leijsi; armature of fourth to ninth segments slightly misplaced because of segment fusion, but also 2 setae missing on fused eighth and ninth segment, and 1 additional small aesthetasc present on sixth segment (maybe homologous to one seta in D. leijsi); penultimate segment about 1.8 times as long as wide. Antenna (Fig. 12F), labrum, mandibula, maxillula (Fig. 12F), maxilla (Fig. 12F), maxilliped (Fig. 12F), all swimming legs (Fig. 10C), and fifth leg (Fig. 10A) as in female. Sixth leg (Fig. 10A) as in D. leijsi.
description: Published as part of Karanovic, Tomislav, 2024, Six new species of Diacyclops (Copepoda: Cyclopoida) from Australia, pp. 101-143 in Zootaxa 5541 (2) on pages 111-115, DOI: 10.11646/zootaxa.5541.2.1, http://zenodo.org/record/14240870