Panaietis satsuma, Uyeno, Daisuke, 2016

Uyeno, Daisuke, 2016, Copepods (Cyclopoida) associated with top shells (Vestigastropoda: Trochoidea: Tegulidae) from coastal waters in southern Japan, with descriptions of three new species, Zootaxa 4200 (1), pp. 109-130 : 119-123

Panaietis satsuma n. sp.

( Figs 7–9 )

Type material. Holotype: adult female ( NSMT –Cr 24626), ex Tectus conus (Gmelin, 1791) ( Vetigastropoda : Trochoidea: Tegulidae ), off Bonomisaki (31°15'N, 130°13'E), Bonotsu, East China Sea, 10 May, 2015, leg. D. Uyeno . Allotype: adult male (NSMT–Cr 24627), collection data same as those of holotype.

Additional material. 2 adult females and 1 adult male ( NSMT –Cr 24628), ex T. pyramis , off Saneku (28°12'N, 129°12'E), Kakeroma Island, Oshima Strait, 29 April, 2015, leg. D. Uyeno, S. Yokoyama . 1 adult male ( NSMT –Cr 24629), ex T. pyramis , off Cape Maeda (26°26'N, 127°46'E), Onna, Okinawa Island, East China Sea, 17 March, 2012, leg. D. Uyeno .

Description of holotype. Adult female. Body ( Fig. 7 A) cyclopiform, 4.81 long, with greatest width at cephalosome; external segmentations distinct. Cephalosome articulated from first pedigerous somite, wider than long, 0.73 × 1.07. First to fourth pedigerous somites and urosomites free. Prosome 2.32 long. Genital somite bearing one pair of lateral lobes ( Fig. 7 A, C), 0.31 × 0.64; genital openings situated on dorsal surface. Abdomen composed of four free somites, 0.38 × 0.37, 0.36 × 0.38, 0.38 × 0.35, and 0.45 × 0.33, respectively. Caudal ramus ( Fig. 7 A, D) 4.24 times longer than wide, 0.43 × 0.10, with six setae.

Rostrum ( Fig. 7 B) triangular without distinct apex. Antennule ( Fig. 7 E) 7-segmented; armature formula 4, 15, 4, 4, 6 + 1 aesthetasc, 2 + 1 aesthetasc, 7 + 1 aesthetasc; all setae small and naked. Antenna ( Fig. 7 F) 3-segmented, composed of coxobasis and 2-segmented endopod; coxobasis large, bearing small, naked seta; first endopodal segment bearing simple seta on inner margin; second endopodal segment bearing four inner elements, inner fused claw, three claws, and two long distal setae. Labrum ( Fig. 7 G) broad, bearing pair of posterior lobes. Mandible ( Fig. 7 H) bearing inner lash-like serrated setulose element and apical serrated setulose element with two hyaline outer teeth at outer lash basis. Maxillule ( Fig. 8 A) represented by simple lobe armed with spherical protrusion and four simple elements. Maxilla ( Fig. 8 B) 2-segmented; basal segment unarmed; terminal segment bearing row of spinules, eight sharp processes, and two small setae. Maxilliped ( Fig. 8 C) 2-segmented, composed of unarmed syncoxa and rod-shaped basis.

Legs 1 to 4 ( Fig. 8 D–G) biramous, bearing 3-segmented rami. Leg armature formula as follows:

Coxa Basis Exopod Endopod

Leg 1 0-0 1-0 I-0; I-0; III, I, 3 0-0; 0-0; II, 1, 2 Leg 2 0-0 1-0 I-0; I-0; III, I, 3 0-0; 0-0; II, I, 2 Leg 3 0-0 1-0 I-0; I-0; III, I, 3 0-0; 0-0; III, I, 2 Leg 4 0-0 1-0 I-0; I-0; III, I, 3 0-0; 0-0; III, I, 1 Basis ( Fig. 8 D–G) of legs 1 to 4 armed with rows of fine spinules near base of endopod. Intercoxal sclerites ( Fig. 8 D–G) of legs 1 to 4 unornamented. All spines spatulate. Legs 1, 2, and 4 bearing distinct pointed projections on rami. Both rami of legs 1 to 4 bearing rows of fine spinules near base of setation elements. Rows of fine spinules present near distal margin of basal endopodal segment of legs 1 to 3 and of middle segment of legs 1 to 4. Leg 5 ( Fig. 8 H) consisting of dorsolateral seta on fifth pedigerous somite and free exopod; exopod pentagonal, bearing three spines and single naked seta. Leg 6 ( Fig. 7 C) represented by two small elements adjacent to genital opening.

Description of allotype. Adult male. Body ( Fig. 9 A) cyclopiform, 3.09 long, depressed dorso-ventrally with greatest width at cephalosome; external segmentations distinct. Cephalosome distinctly articulated from first pedigerous somite, wider than long, 0.52 × 0.71. First to fourth pedigerous somites and urosomites free. Prosome 1.51 long. Genital somite ( Fig. 9 A, B) 0.22 × 0.32. Abdomen progressively narrower posteriorly, composed of four free somites, 0.23 × 0.26, 0.28 × 0.24, 0.19 × 0.22, and 0.25 × 0.20, respectively. Caudal ramus ( Fig. 9 A) 3.27 times longer than wide, 0.24 × 0.07, with six setae.

Antennule, antenna, mandible, maxillule, and maxilla as in female. Maxilliped ( Fig. 9 C) 4-segmented; basal segment rod-like; second segment bearing two setae and row of spinules; third segment small with single element; terminal claw curved, bearing two basal elements and row of spinules on inner margin. Armature formula of legs 1 to 4 as in female. Leg 5 as in female. Leg 6 ( Fig. 9 B) represented by two simple setae on genital operculum.

Variability. The morphology of other female specimens as in the holotype. Measurements of body parts (n = 2) as follows: body length 4.18–4.26 (4.22 ± 0.06); cephalosome length 0.72–0.88 (0.80 ± 0.11); cephalosome width 1.05–1.15 (1.10 ± 0.07); prosome length 1.75; genital somite length 0.22–0.30 (0.26 ± 0.05); genital somite width 0.70–0.85 (0.77 ± 0.10); first urosomite length 0.29; first urosomite width 0.43–0.56 (0.50 ± 0.09); second urosomite length 0.44–0.50 (0.47 ± 0.04); second urosomite width 0.39–0.49 (0.44 ± 0.07); third urosomite length 0.35–0.45 (0.40 ± 0.07); third urosomite width 0.35–0.47 (0.41 ± 0.08); anal somite length 0.44–0.51 (0.47 ± 0.05); anal somite width 0.32–0.41 (0.36 ± 0.07); caudal ramus length 0.46–0.55 (0.50 ± 0.06); caudal ramus width 0.12–0.15 (0.13 ± 0.03). Caudal ramus 3.55–4.00 (3.78 ± 0.32) times longer than wide.

Morphology of the other male specimens as in allotype. Measurements of body parts of other male specimens (n = 2) as follows: body length 3.22–3.38 (3.30 ± 0.11); cephalosome length 0.55–0.61 (0.58 ± 0.04); cephalosome width 0.82–0.85 (0.83 ± 0.02); prosome length 1.38–1.58 (1.48 ± 0.14); genital somite length 0.22–0.24 (0.23 ± 0.01); genital somite width 0.36–0.38 (0.37 ± 0.02); first urosomite length 0.25–0.28 (0.27 ± 0.02); first urosomite width 0.29–0.31 (0.30 ± 0.01); second urosomite length 0.32; second urosomite width 0.27–0.29 (0.28 ± 0.02); third urosomite length 0.23–0.29 (0.26 ± 0.04); third urosomite width 0.24–0.27 (0.25 ± 0.02); anal somite length 0.33–0.36 (0.35 ± 0.02); anal somite width 0.22–0.23 (0.22 ± 0.01); caudal ramus length 0.32–0.34 (0.33 ± 0.01); caudal ramus width 0.08. Caudal ramus 3.82–4.00 (3.91 ± 0.13) times longer than wide.

Remarks. Panaietis satsuma n. sp. differs from P. haliotis and P. malleolata in both rami of legs 1 to 4 bearing spatulate spines in female (vs. slender pointed spines) (see Sars 1918, pl. CXII; Yamaguti 1936, figs 21–24). The new species is distinguished from P. yamagutii by having the free exopod of leg 5 situated on the lateral surface of the pedigerous somite in both sexes (vs. located posteroventrally on pedigerous somite) (see Izawa 1976, fig. 37, 50). Panaietis satsuma n. sp. is distinguished from P. incamerata and P. doraconis n. sp. by having a pentagonal free exopod on leg 5 (vs. rod-like shaped) (present study).

Attachment site. The pharynx and esophagus.

Etymology. The specific name, satsuma , is derived from the old name of the type locality, Kagoshima prefecture. The name is used as a noun in apposition.

Newly established Japanese name for species. Benishiridaka-no-haramushi.

Figures

FIGURE 7. Panaietis satsuma n. sp., adult female, holotype NSMT – Cr 24626. A, habitus, dorsal; B, rostral area; C, genital aperture and leg 6, dorsal; D, right caudal ramus, dorsal; E, right antennule; F, left antenna, anterior; G, labrum, anterior; H, right mandible, anterior. Scale bars: A, 1 mm; B, 200 µm; C, G, H, 50 µm; D – F, 100 µm.

FIGURE 8. Panaietis satsuma n. sp., adult female, holotype NSMT – Cr 24626. A, left maxillule, anterior; B, right maxilla, posterior; C, left maxilliped, anterior; D, left leg 1, anterior; E, right leg 2, anterior; F, right leg 3, anterior; G, left leg 4, anterior; H, left leg 5, ventral. Scale bars: A, 20 µm; B, C, H, 50 µm; D – G, 100 µm.

FIGURE 9. Panaietis satsuma n. sp., adult male, allotype NSMT – Cr 24627. A, habitus, dorsal; B, genital somite, ventral; C, right maxilliped, inner. Scale bars: A, 500 µm; B, 100 µm; C, 50 µm.