Cyclopina wido, Karanovic, 2020

Karanovic, Tomislav, 2020, Four new Cyclopina (Copepoda, Cyclopinidae) from South Korea, ZooKeys 992, pp. 59-104 : 59

Cyclopina wido sp. nov. Figures 14 , 15 , 16 , 17D

Type locality.

South Korea, West Coast, Wido Island, small beach, intertidal sand, 35°35.089'N, 126°15.196'E.

Specimens examined.

Holotype ovigerous female dissected on one slide, collected from the type locality, 12 April 2013, leg. T. Karanovic.

Paratypes: one male (allotype) dissected on one slide; one female on one SEM stub (together with specimens of other three species described here; row no. 1); both collected from the type locality, 12 April 2013, leg. T. Karanovic.

Etymology.

The species name refers to its type locality (Wido). It should be treated as a noun (gender feminine) in apposition to the generic name.

Description.

Female (based on holotype and one paratype). Body length of holotype 327 μm, that of paratype 323 μm. Colour of preserved specimens yellowish, nauplius eye not visible (Fig. 17D ). Integument on all somites (Fig. 14 ) smooth, with moderate bacterial cover, cuticular pores on all somites, spinules only on genital somite and caudal rami, and sensilla on all but penultimate somite; hyaline fringes of prosomites smooth, of urosomites serrated. Habitus ca. 2.6 × as long as wide in dorsal view, with pronounced distinction between prosome and urosome; prosome ovoid but with more flared posterior end than in C. busanensis , ca. 1.6 × as long as wide in dorsal view, nearly 1.6 × as long and 2.7 × as wide as urosome, its greatest width at posterior end of first pedigerous somite; urosome nearly cylindrical, ca. 3 × as long as wide, its greatest width at posterior end of fifth pedigerous somite (first urosomite). First pedigerous somite (Fig. 14B ) not fused to cephalothorax, but its tergites largely covered with posterior extensions of cephalothoracic shield. Cephalothorax (Fig. 14A ) shape as in C. busanensis , nearly conical, approximately as long as wide, and 1.2 × as long as free prosomites combined; however, cuticular sensilla and pores pattern unique. Second to fourth free prosomites (Fig. 14B, C ) progressively shorter and narrower towards posterior end, and with fewer cuticular organs; not many prosomal cuticular organs obviously homologous to those in previous species, except perhaps dorsal medial pores and several posterior sensilla.

First urosomite (Fig. 14D ) as in C. busanensis and C. koreana , short, slightly laterally expanded in posterior part, with two pairs of dorsal sensilla, single dorsal medial pore, one pair of dorsolateral pores, and one pair of ventrolateral pores (at base of fifth legs).

Genital double-somite (Figs 14E , 15A ) as in C. busanensis , except ventral posterior pores slightly closer to ventral posterior sensilla, pair of small lateral anterior pores closer to sixth leg, somite ca. 1.1 × as long as wide, and laterally expanded anterior part nearly 1.4 × as wide as posterior margin. Copulatory pore, copulatory duct, seminal receptacles, oviducts, and genital apertures as in C. busanensis . Fourth urosomite (Figs 14F , 15A ) ca. half as long as genital double-somite, with sensilla and pores as in C. busanensis . Fifth urosomite (Figs 14G , 15A ) almost as long as fourth urosomite, with medial dorsal pore and one pair of widely spaced ventral pores as in C. busanensis , but dorsal hyaline fringe coarsely serrated and expanded posteriorly almost as pseudo-operculum (completely covering anal operculum). Sixth urosomite (Figs 14G , 15A ) 0.85 × as long as fifth urosomite, with one pair of dorsal sensilla, two pairs of dorsal pores, and single pair of ventral pores; no spinules on fringes of narrow anal sinus; anal operculum smooth, very short, narrow, slightly concave, situated in first fourth, represents approximately 40% of somite’s width.

Caudal rami (Figs 14H , 7H , 8H , 9A ) robust, cylindrical, ca. 2.3 × as long as wide and 1.4 × as long as anal somite, very narrowly spaced on anal somite, nearly parallel; armed with six setae as in C. busanensis ; ornamented with single pore near proximal lateral seta, row of small spinules at base of proximal lateral seta, posterior ventral row of spinules, and short diagonal dorsomedial row of large spinules in anterior half. Proximal lateral seta inserted at ca. two fifths of ramus’ length; medial terminal seta only ca. 0.6 × as long as caudal ramus, 1.2 × as long as lateral terminal seta, 0.6 × as long as dorsal seta, and 1.6 × as long as proximal lateral seta.

Antennula (Fig. 15B ) 10-segmented, very stout, nearly cylindrical (proximal part only slightly wider than distal part); armature formula 3.5.5.4.4.6.3.3.2.7+ae; apical aesthetasc significantly shorter than in C. busanensis and fifth segment with two short setae, as in C. koreana ; sixth segment longest, ca. 1.5 × as long as wide, and 0.6 × as long as subsequent four segments combined; tenth segment ca. 1.3 × as long as wide.

Antenna (Fig. 16A ) shape, segmentation, most ornamentation, and most armature as in C. koreana , but no exopodal setae and inner-distal seta on basis significantly shorter.

Mandibula (Fig. 16B ) as in C. koreana , except cutting edge somewhat narrower, basis slenderer, exopod stouter, setae on fourth exopodal segment of equal length, and no spinules at base of unicuspid teeth.

Maxillula (Fig. 16C ) as in C. koreana , except endopod shorter and with only six setae, as well as setae on distal basal endite of equal length.

Maxilla (Fig. 16D ) as in C. curtijeju , i.e., with only two setae on second endopodal segment.

Maxilliped (Fig. 16E ) as in C. koreana , except apical setae slightly shorter.

Swimming legs (Fig. 16F-I ) shape, most segmentation, most ornamentation, and most armature as in C. busanensis , except endopod of first leg two-segmented and with one less seta, as well as second endopodal segments of second to fourth legs with single medial seta; all spines lanceolate and all setae slender; third exopodal segment seta formula 4.5.5.5 and spine formula 4.4.4.3; third endopodal segment of fourth leg 1.3 × as long as wide and third exopodal segment of fourth leg only ca. 1.1 × as long as wide.

Fifth leg (Fig. 16J ) shape, segmentation, armature formula, and ornamentation as in C. koreana , but second segment longer and lateral spine shorter than medial; second segment ca. 1.9 × as long as first segment and ca. 1.7 × as long as wide; lateral spine ca. 0.5 × as long as second segment and 0.7 × as long as medial spine.

Sixth leg (Fig. 14E ) as in C. busanensis .

Male (based on allotype). Body length 305 μm. Habitus similar to female, but slightly slenderer. Urosome (Fig. 15C ) also slenderer than in female, and second and third urosomites fully articulated as in C. busanensis ; ornamentation as in female.

Caudal rami (Fig. 15C ) slightly shorter and slenderer than in female, but armature and ornamentation without significant differences.

Antennula (Fig. 15D ) geniculation, segmentation, ornamentation, and all armature as in C. koreana , but all segments shorter.

Antenna, mandibula, maxillula, maxilla, maxilliped, and all four swimming legs (Fig. 16K-M ) as in female. Endopod of first leg (Fig. 16K ) also two-segmented, with only seven setae; third endopodal segment of fourth leg (Fig. 16L ) nearly 1.4 × as long as wide; third exopodal segment of fourth leg (Fig. 16M ) ca. 1.2 × as long as wide.

Fifth leg (Fig. 15C ) segmentation, ornamentation, and armature formula as in C. busanensis , except second segment more rounded and lateral spine shorter; second segment twice as long as first segment and 1.5 × as long as wide; lateral spine ca. 0.6 × as long as distal segment and 0.9 × as long as medial spine.

Sixth leg (Fig. 15C ) without medial spine as in C. koreana ; lateral seta 1.4 × as long as medial seta.

Variability.

Only one male and two females were examined, so variability could not be properly assessed. One female was examined in detail with a light microscope (holotype), and the other with a scanning electron microscope (paratype). However, the paratype female was also beforehand examined with a light microscope (although without dissection) and no variability was observed in the most important diagnostic characters (caudal rami length, antennula segmentation, swimming legs segmentation and armature, or fifth leg proportions); mouth appendages could not be examined without dissection. Male characters that are not sexually dimorphic show only minute differences from female characters in proportions of somites, segments, or armature.

Figures

Figure 7. Cyclopina koreana sp. nov., paratype female 1, SEM photographs, all in dorsal view A habitus B second pedigerous somite C third pedigerous somite D first urosomite E genital double-somite and fourth urosomite F anterior medial pore on genital double-somite G fifth and sixth urosomites H caudal ramus.

Figure 8. Cyclopina koreana sp. nov., SEM photographs A-E paratype male 1, ventral view F-H paratype female 2, lateral view: A habitus B distal part of antennula C fourth swimming leg D fourth and fifth urosomites E sixth urosomite F tergite of fourth pedigerous somite G anterior part of urosomite, with fifth and sixth legs H fifth and sixth urosomites.

Figure 9. Cyclopina koreana sp. nov., line drawings A holotype female, urosome, ventral view B holotype female, antennula C allotype male, urosome, ventral view.

Figure 14. Cyclopina wido sp. nov., paratype female 1, SEM photographs, all in dorsal view A posterior part of cephalothorax B first and second pedigerous somites C third and fourth pedigerous somites D first urosomite E sixth leg F posterior part of genital double-somite and fourth urosomite G hyaline fringe of fifth urosomite and sixth urosomite H caudal rami.

Figure 15. Cyclopina wido sp. nov., line drawings A, B holotype female C, D allotype male: A urosome without first urosomal somite, ventral view B antennula C urosome, ventral view D penultimate and ultimate segments of antennula.

Figure 16. Cyclopina wido sp. nov., line drawings A-J holotype female K-M allotype male: A antenna, without apical armature B mandibula C maxillular palp D endopod of maxilla E last four endopodal segments of maxilliped F first swimming leg G third exopodal segment of second swimming leg H endopod of second swimming leg I fourth swimming leg J fifth leg K endopod of first swimming leg L third endopodal segment of fourth swimming leg M third exopodal segment of fourth swimming leg.

Figure 17. Light photographs of four new species (not to scale) A Cyclopina busanensis sp. nov., four females (two ovigerous) B Cyclopina koreana sp. nov., three females and four males C Cyclopina curtijeju sp. nov., two females D Cyclopina wido sp. nov., two females (one ovigerous) and one male.