Schizopera sindoensis, Karanovic, Tomislav & Cho, Joo-Lae, 2016

Karanovic, Tomislav & Cho, Joo-Lae, 2016, Four new Schizopera (Copepoda, Harpacticoida) from marine interstitial habitats in Korea, Zootaxa 4114 (1), pp. 1-32 : 20-28

publication ID	https://doi.org/ 10.11646/zootaxa.4114.1.1
publication LSID	lsid:zoobank.org:pub:B09ECE6E-3D79-47F0-B3B3-84823B28993D
DOI	https://doi.org/10.5281/zenodo.6062720
persistent identifier	https://treatment.plazi.org/id/1E50A92E-FF8A-FFE1-C6B6-F55DFC9EBEE2
treatment provided by	Plazi
scientific name	Schizopera sindoensis
status	sp. nov.

Treatment

Schizopera sindoensis sp. nov.

( Figs. 10 View FIGURE 10 , 11 View FIGURE 11 , 12 View FIGURE 12 B–D, 13-15, 16D)

Type locality. South Coast of Korea, Jeju Island, Sindo port, exposed small beach just north from port, 33°16.690’N 126°10.185’E.

Specimens examined. Holotype female ( NIBR IV 0000287251), allotype male ( NIBR IV 0000287252), and one paratype male ( NIBR IV 0000287253), each dissected on one slide; two paratype males ( NIBR IV 0000287255) together on one SEM stub; one paratype male and one paratype copepodid together in ethanol ( NIBR IV 0000287256); all collected from the type locality, 25 April 2014, leg. T. Karanovic.

Etymology. The species is named after the type locality, Sindo port, with the addition of the Latin suffix for place “- ensis ”. The specific name consequently is an adjective for place.

Description. Female (holotype). Total body length about 515 µm. Colour of preserved specimen, habitus, nauplius eye, body segmentation, integument thickness, and surface and general shape of somites as in S. daejinensis . Rostrum ( Fig. 13 View FIGURE 13 B) about 2.5 times as long as wide, with more pointed tip than in S. daejinensis . All somites, except for cephalothorax, besides sensilla and pores ornamented also with at least one row of minute spinules in anterior half. Hyaline fringe of all somites broad; those of all prosomites smooth, those of urosomites finely serrated. Surface of somites, rostrum, and caudal rami with total of 71 pairs of cuticular organs (13 pairs of cuticular pores and 58 pairs of sensilla) and one unpaired dorsal sensillum. All sensilla and pores homologous to those in S. daejinensis , S. yeonghaensis , and S. gangneungensis .

Cephalothorax without pair of sensilla at base of rostrum (C-2), and with only one pair of pores (C-VI), all other sensilla (C-2 to C-30) as in S. daejinensis .

Pleurons of free prosomites as in S. daejinensis , with seven (FP1-1 to FP1-7), five (FP2-1 to FP2-5) and six (FP3-1 to FP3-6) pairs of sensilla respectively, additionally ornamented with one or two dorsal anterior rows of minute spinules.

First urosomite as in S. daejinensis , but with anterior dorsal row of minute spinules.

Second urosomite ( Fig. 13 View FIGURE 13 A) as in S. daejinensis completely fused with third urosomite into genital doublesomite, with three pairs of dorsal posterior sensilla (U2-1 to U2-3) but only one pair of ventral pores, probably homologous to those in S. gangneungensis (U 2-IV). Genital complex similar to that of S. daejinensis ; epicopulatory bulb large about 1.5 times as long as wide; seminal receptacles reaching anterior margin of epicopulatory bulb, about 0.6 times as long as epicopulatory bulb.

Third, fourth, fifth, and sixth urosomites ( Fig. 13 View FIGURE 13 A) as in S. daejinensis , but with more minute spinules in anterior part.

Caudal rami ( Fig. 13 View FIGURE 13 A) not very strongly sclerotized, short and wide, only about 1.1 times as long as wide in ventral view, almost conical (tapering towards caudal end continuously from base and along both outer and inner margins), with space between rami very small; general ornamentation as in S. gangneungensis (i.e. with two ventral and two dorsal pair of pores), but without dorsal rows of minutes spinules and with inner spinules more slender; armed as in S. daejinensis with six elements, but their proportions somewhat different. Dorsal seta about as long as ramus; lateral proximal spine 0.6 times as long as ramus; lateral distal seta slightly longer than ramus; innermost apical seta about 0.35 times as long as ramus; central apical seta about 3.5 times as long as caudal ramus; outer apical seta about twice as long as caudal ramus.

Antennula ( Fig. 13 View FIGURE 13 B) segmentation, ornamentation and armature formula as in S. daejinensis , except for one additional seta present on third segment, and for first segment without spinules. One antennula abnormal, with reduced armature and ornamentation in distal part ( Fig. 13 View FIGURE 13 C).

Antenna ( Fig. 13 View FIGURE 13 D) segmentation, armature and most ornamentation as in S. daejinensis ; coxa about 0.8 times as long as wide; allobasis 1.9 times as long as wide and 2.2 times as long as coxa; second exopodal segment with more distal spinules, about three times as long as wide and 1.1 times as long as first segment.

Labrum, mandibula, maxillula, and maxilla as in S. daejinensis (not illustrated).

Maxilliped ( Fig. 13 View FIGURE 13 E) segmentation, armature, and most ornamentation as in S. daejinensis ; first endopodal segment about 3.2 times as long as wide and 1.6 times as long as coxobasis, slightly ovoid, ornamented as in S. daejinensis ; second endopodal segment 0.35 times as long as first and three times as long as wide; apical spine 1.9 times as long as second endopodal segment and 1.5 times as long as longest seta.

All swimming legs ( Fig. 14 View FIGURE 14 A, B, C) proportions, segmentation, most armature, and most ornamentation as in S. daejinensis .

First swimming leg ( Fig. 14 View FIGURE 14 A) as in S. daejinensis , except for much shorter inner seta on first endopodal segment, and for first endopodal segment about as long as entire exopod, 4.7 times as long as second endopodal segment, and about 4.5 times as long as wide.

Second swimming leg ( Fig. 14 View FIGURE 14 B) as in S. daejinensis , except for second exopodal segment without inner seta and second endopodal segment with shorter inner seta.

Third swimming leg ( Fig. 14 View FIGURE 14 B) similar to second swimming leg, except for basis with slender outer seta and first endopodal segment with short and strong inner seta.

Fourth swimming leg as in S. daejinensis , except for with shorter inner setae on first two endopodal segments.

Fifth leg ( Fig. 14 View FIGURE 14 D) shape, segmentation, armature, and most ornamentation as in S. daejinensis ; exopod less ovoid, 1.45 times as long as wide, with division line visible on both posterior and anterior surfaces; length ratio of exopodal armature elements, from inner side, 1: 3.6: 2.3: 1: 0.8: 1.6; length ratio of endopodal armature elements, from inner side, 1: 1.9: 2.7: 2.2.

Sixth leg ( Fig. 13 View FIGURE 13 A) as in S. daejinensis , except for inner seta about 2.1 times as long as outer seta.

Male (based on allotype and two paratypes). Body length from 380 to 415 µm. Segmentation as in female, except for genital somite and third urosomal somite not fused. Habitus ( Figs. 10 View FIGURE 10 A, 11B) slightly more slender than in female, but also cylindrical, and with similar proportions; body length/width ratio about 5.3 in dorsal view. Ornamentation of rostrum ( Figs. 11 View FIGURE 11 F, 15C), prosomites ( Figs. 10 View FIGURE 10 B, C, 11B, C), and first urosomite ( Figs. 10 View FIGURE 10 C, 11C), as well as colour and nauplius eye, as in female; cephalothorax without pair of sensilla at base of rostrum (C- 2).

Genital somite ( Figs. 10 View FIGURE 10 D, 11D, 15A) more than twice as wide as long; ornamentation consists of three pairs of large dorsal sensilla (U2-1 to U2-3) and single pairs of ventral pores, probably homologous to those in female (U 2- IV). Ovoid spermatophore ( Fig. 15 View FIGURE 15 B) longitudinally placed inside genital somite, about 2.4 times as long as wide.

Third urosomite ( Figs. 10 View FIGURE 10 D, 11D, 15A) ornamented as in female, but not fused to second (genital) urosomite, with ventral pair of sensilla (U3-3) less widely spaced, with dorsolateral pair of pores probably homologous to those of S. yeonghaensis (U 3-I) and one novel pair of anterior ventral pores (U 3-III).

Fourth and fifth urosomites ( Figs. 10 View FIGURE 10 E, 11E, 15A) as in female, but with dorsolateral and ventral pairs of pores (U 4-I, U 4-III, U 5-I, and U 5-III), serially homologous to those on third urosomite.

Sixth urosomite ( Figs. 10 View FIGURE 10 E, F, 11E, 15A) as in female, but with two additional ventral pairs of pores (U 6-II and U 6- III) as novel structures among Korean species.

Caudal rami ( Figs. 10 View FIGURE 10 F, 11E, 15A) slightly shorter in comparison with anal somite and less bulbous than in female but hardly any difference in armature or ornamentation, except for inner margin with fewer spinules.

Antennula ( Figs. 11 View FIGURE 11 F, 12B, 15C) similar to that of S. yeonghaensis but 8-segmented (female’s sixth segment not fully subdivided); however without observable difference in armature or ornamentation.

Antenna, labrum, mandibula, maxillula, maxilla, maxilliped, exopod and endopod of first swimming leg, exopod of second swimming leg, endopod of third swimming leg, and fourth swimming leg as in female.

First swimming leg ( Figs. 12 View FIGURE 12 C, 15D) with modified basis, similar to that of S. yeonghaensis but with large spinules along inner margin and with inner spine significantly longer than spiniform process.

Second swimming leg ( Fig. 15 View FIGURE 15 E) with transformed endopod as in S. yeonghaensis , although slightly less slender and with shorter and more robust inner seta on third segment.

Third swimming leg ( Fig. 15 View FIGURE 15 F) as in S. yeonghaensis with very characteristic element on anterior surface of third exopodal segment.

Fifth legs ( Figs. 12 View FIGURE 12 D, 15G) segmentation, armature and most ornamentation as in S yeonghaensis , except for anterior pore not on endopodal lobe but on outer basal part, and innermost exopodal spine much more robust; exopod slightly longer than wide, length ratio of exopodal armature elements, from inner side, 1: 3: 2.6: 0.7: 1.1.

Sixth legs ( Figs. 10 View FIGURE 10 D, 15A) expressed as pair of small, short cuticular plates, without armature, ornamentation or demarcation; left one larger and probably functioning as genital flap.

Variability. Only one female of this species was collected and examined, and it had one antennula abnormal, with a reduced armature and segmentation in the distal part ( Fig. 13 View FIGURE 13 C), while the other antennula was normal ( Fig. 13 View FIGURE 13 B). This is probably a developmental anomaly resulting from physical or chemical damage. All males had additional urosomal pores, not observed in the single female studied. It is impossible at this stage to determine if these are also part of sexual dimorphism, or if they are part of sex-independent intraspecific variability. All other urosomal and all prosomal cuticular organs were identical in both sexes.