Parakermania longa sp. nov.

Figs 1–2

Holotype. Male, CHINA: Hainan Island, Chengmai (19°43′N, 110°01′E), a secondary broad-leaved forest near Road 303, 26.v.2021, leg. Yutao Wang, prep. slide nos. L20182−20184 . Paratypes. Three males, two females, same collection data as holotype .

Diagnosis. Body with thin and long ornamentations on outer sides of pereonite 6, conspicuously reaching beyond apex of telson.

Description. Body length of males 2.0–3.0 mm, of females 3.0– 3.5 mm. Body elliptic, able to roll up into ball; head white, pale yellow mixed with pale brown on cephalon and around ommatidia, cephalon with frontal shield slightly protruding over vertex; dorsum pale brown mixed with pale yellow; each pereonite with six tubercles except for pereonite 7 with three tubercles, outer tubercles on pereonite 6 developed into two thin and long ornamentations going beyond apex of telson, median tubercle on pereonite 7 enlarged into thumb-shaped projection; epimera of pereonite 1 round, pereonites 2−7 with triangular epimera (Fig. 1A–C); pereonites 1 and 2 with small lobe and large tooth on ventral side (Fig. 1D).

Antennula composed of three articles, distal article bearing apical set of small aesthetascs (Fig. 2A). Antenna short and stout, second article of flagellum twice as long as first article (Fig. 2B).

Mandibles with molar process reduces to single plumose seta (Fig. 2C, D). Maxillula with outer branch bearing 4+6 teeth, inner branch with two stout penicils (Fig. 2E). Maxilla distally bilobate, with inner lobe distinctly narrower than outer lobe (Fig. 2F). Maxilliped with three long setae on apical margin of endite, palp two-jointed (Fig. 2G).

Pereopod 1 and 7 without particular modifications (Fig. 2H, I).

Pleopods, sexual differentiation. Male pleopod 1 exopodite small bean-shaped, no visible respiratory structures (Fig. 2J); endopodite with broad basal part, narrowed towards apical tip, apex beak-shaped and covered with tiny spines (Fig. 2K). Pleopod 2 exopodite concave on outer margin, inner margin basally convex, narrowed towards apical tip (Fig. 2L); endopodite thin and long, distinctly longer than exopodite (Fig. 2M). Telson with nearly quadrangular distal part, distal part about half as wide as basal part, ending with convex apical margin; uropodal protopodite nearly trapezoidal, postero-lateral corners broadly rounded; minute exopodites inserted dorsally beneath small tooth (Fig. 2N, O).

Distribution. China (Hainan).

Etymology. The specific name is derived from the Latin longus = long, in reference to the species has two long ornamentations on the outer sides of the sixth pereonite.

Remarks. This new species shares common derived characters with other two congeners ( P. minima Vandel, 1973 and P. maculata Kwon & Taiti, 1993) in having well-developed tubercles on dorsum of body, short and stout antenna, triangular epimera on pereonites 2−7, small lobe on ventrum of pereonite 1 and large ventral tooth on pereonite 2 (Fig. 1). But it can be distinguished from the latter species by 39 dorsal tubercles on pereonites, and two outer tubercles on pereonite 6 developed into thin and long ornamentations reaching beyond apex of telson (Fig. 1A–C). In P. minima, pereonites have 63 dorsal tubercles, and outer tubercles on pereonites 1–6 developed into long spine-shaped projections, but not reaching telson (Vandel 1973: fig. 109). In P. maculata, dorsum of pereonites covered with 60 small rounded tubercles (Kwon & Taiti 1993: fig. 315).