Diacyclops eberhardi, Karanovic, 2024

Karanovic, Tomislav, 2024, Six new species of Diacyclops (Copepoda: Cyclopoida) from Australia, Zootaxa 5541 (2), pp. 101-143 : 111-115

publication ID	https://doi.org/ 10.11646/zootaxa.5541.2.1
publication LSID	lsid:zoobank.org:pub:86A7CD79-F5A2-4AA6-A6AA-01C0CB64B29C
DOI	https://doi.org/10.5281/zenodo.14248343
persistent identifier	https://treatment.plazi.org/id/03E8C55F-9C00-FFD9-FF0B-96E8FD10658B
treatment provided by	Plazi
scientific name	Diacyclops eberhardi
status	sp. nov.

Treatment

Diacyclops eberhardi sp. nov.

( Figs. 1B View FIGURE 1 , 8–12 View FIGURE 8 View FIGURE 9 View FIGURE 10 View FIGURE 11 View FIGURE 12 )

urn:lsid:zoobank.org:act:66BA5A5F-161F-46F8-B638-614CC67D06CB

Type locality. Western Australia, Margaret River, Easter Cave GoogleMaps , 34.274367°S 115.099297°E, 12 March 2002, collected by S. Eberhard.

Holotype. Adult female dissected on 1 microscope slide GoogleMaps .

Paratypes. One male from type locality dissected on 1 microscope slide; GoogleMaps 2 males and 2 females from type locality on 1 SEM stub (row no. 5), together with 5 other species described here; GoogleMaps 3 males and 11 copepodids from type locality in 1 alcohol vial GoogleMaps ; 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. GoogleMaps

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 View FIGURE 1 , 11A View FIGURE 11 ) 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 View FIGURE 11 ) 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 View FIGURE 11 ) and first urosomite ( Fig. 11D View FIGURE 11 ) smooth, those of genital double-somite and 2 subsequent urosomites ( Fig. 11E View FIGURE 11 ) slightly wavy. Genital double-somite ( Fig. 8A View FIGURE 8 ) 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 View FIGURE 8 , 11E View FIGURE 11 ) with large spinules along ventral margin. Caudal rami ( Figs. 8A View FIGURE 8 , 11F View FIGURE 11 ) 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 View FIGURE 8 ) 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 View FIGURE 8 ) 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 View FIGURE 8 ), maxillula ( Fig. 8E View FIGURE 8 ), maxilla ( Fig. 8F View FIGURE 8 ), and maxilliped as in D. leijsi . Segmentation of all swimming legs ( Fig. 9A, B, C, D, E View FIGURE 9 ) 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 View FIGURE 8 , 9F View FIGURE 9 ) 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 View FIGURE 9 ) 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 View FIGURE 12 ) and urosome ( Fig. 10A View FIGURE 10 ) slightly slenderer than in female; free genital somite ( Fig. 10A View FIGURE 10 ) about 1.6 times as wide as subsequent urosomite, with relatively large ovoid spermatophores. Ornamentation of cephalothorax ( Fig. 12B View FIGURE 12 ), free prosomites ( Fig. 12C View FIGURE 12 ), and urosomites ( Figs. 10A View FIGURE 10 , 12A, D View FIGURE 12 ) as in female. Anal somite ( Figs. 10A View FIGURE 10 , 12A View FIGURE 12 ) shorter than in female and with smaller ventral spinules. Caudal rami ( Figs. 10A View FIGURE 10 , 12A View FIGURE 12 ) slightly slenderer than in female, with shorter dorsal seta. Antennula ( Figs. 10B View FIGURE 10 , 12E View FIGURE 12 ) 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 View FIGURE 12 ), labrum, mandibula, maxillula ( Fig. 12F View FIGURE 12 ), maxilla ( Fig. 12F View FIGURE 12 ), maxilliped ( Fig. 12F View FIGURE 12 ), all swimming legs ( Fig. 10C View FIGURE 10 ), and fifth leg ( Fig. 10A View FIGURE 10 ) as in female. Sixth leg ( Fig. 10A View FIGURE 10 ) as in D. leijsi .