Parapenaeon sicyoniae, An & Markham & Li, 2015

An, Jianmei, Markham, John C. & Li, Xinzheng, 2015, A review of the genus Parapenaeon Richardson, 1904 (Crustacea: Isopoda: Bopyridae: Orbioninae), with description of three new species from China, Journal of Natural History 49 (41), pp. 2527-2557 : 2548-2550

Parapenaeon sicyoniae sp. nov.

( Figures 9 , 10 )

Material examined

Infesting Sicyonia lancifer ( Olivier, 1811) [= Sicyonia cristata de Haan, 1844 ]. Holotype: CIEPE560309 , ♀, allotype: CIEPE560310 , ♂, Haimen , Guangdong Province, 23°15 ′ N, 116°40 ′ E, 14 March 1956, coll. Ruiyu Liu. Paratypes: CIEPE560307 , 2♀♀, 2♂♂, Haimen , Guangdong Province, 23°15 ′ N, 116°40 ′ E, 14 March 1956, coll. Ruiyu Liu.

Description of holotype female (CIEPE560309) ( Figure 9A, O )

Length 5.79 mm, maximal width 4.23 mm, head length 0.96 mm, head width 1.37 mm.

Head oval, with well-developed frontal lamina. Small black eyes on boundary between frontal lamina and head ( Figure 9A ). First antenna of three articles without evident setae, basal two articles stout, terminal article very narrow; second antenna of four articles, each much narrower than that proximal to it, terminal article with sparse setae ( Figure 9C ). Palp of maxilliped broadly triangular, offset slightly from medial margin, non-setose, not articulating with maxilliped ( Figure 9D ). Barbula with two pairs of digitate lateral projections on each side, more branches on outer projections than inner ones. Small tubercule medial to each inner projection ( Figure 9E ).

Pereon broadest across third pereomere ( Figure 9A ). Coxal plates well-developed on long side of all pereomeres. Coxal plates on short side of first two pereomeres also well-developed, but those on third and fourth pereomeres rudimentary, absent from other pereomeres. Round dorsolateral bosses on first four pereomeres. Brood pouch almost closed ( Figure 9B ). First oostegite ( Figure 9F, G ) with slightly sinuate internal ridge. Roundly triangular posterolateral point extending posterolaterally. Pereopods larger posteriorly ( Figure 9H, I ), all bases produced into lobes.

Pleon of six pleomeres, first five bearing smooth lateral plates ( Figure 9J ) and biramous digitate pleopods ( Figure 9K–O ). Sixth pleomeres visible in dorsal view, with digitate biramous uropods ( Figure 9J ). Exopodites of uropods round, endopodites as slender triangles.

Figures

Figure 9. Parapenaeon sicyoniae n. sp. Holotype female (CIEPE560309) (A–O). (A) Dorsal view; (B) ventral view; (C) left antennae; (D) left maxilliped, external view; (E) left side of the barbula; (F) left oostegite 1, external view; (G) left oostegite 1, internal view; (H) left pereopod 1; (I) left pereopod 7; (J) ventral view of lateral plates and uropods (exclude the pleopods); (K) right pleopod 1; (L) right pleopod 2; (M) right pleopod 3; (N) right pleopod 4; (O) right pleopod 5. Allotype male (CIEPE560310) (P, Q). (P) Dorsal view; (Q) ventral view. Scale bars: A, B, 1 mm; C, H, I, 0.22 mm; D, E, 0.36 mm; F, G, 0.42 mm; J, 0.65 mm; K–O, 0.47 mm; P, Q, 0.38 mm.

Figure 10. Parapenaeon sicyoniae sp. nov. Scanning electron microsgraphs of paratype male (CIEPE560307) (A–D). (A) Ventral view of the male; (B) left antennae and left pereopod 1; (C) right pereopods 1–3; (D) right pereopod 7. Scale bars: A, 1 mm; B–D, 100 µm.