IUCN threat status:

Not evaluated

Comprehensive Description

Read full entry

Description

Carapace (Figs 2 and 3). Carapace rounded trapezial in lateral view with very slight protrusion on antero-ventral area and sharp wrinkle-like groove running from middle to posterior in ventral area of both valves. Anterior margin tapers more than posterior margin. Dorsal margin slightly rounded. Ventral margin almost straight. Carapace surface generally smooth. All pore systems of simple type and 42 per valve. Seven and four marginal pores along anterior and posterior margins, respectively. Marginal infold broad in anterior area but very narrow in posterior area. Vestibula occupying large part of marginal infold. Inner surface covered with numerous pits. Hingement modified pentodont type. Right valve slightly overlapping left valve along hinge line. Four adductor muscle scars in oblique row. Mandibular scar visible beneath frontal scar.  Antennula (Fig. 4A). Five articulated podomeres. First podomere bare and short. Second podomere nine quarters as long as first podomere, with fine setae along antero-distal margin. Third podomere half as long as second podomere, with one medium seta on antero-distal end. Fourth podomere as long as third podomere, with two long setae on antero-distal end and one long seta on postero-distal end. Fifth podomere half as long as fourth podomere, with one long and one very long simple setae and one spatula-like long seta on distal end.  Antenna (Fig. 4B). Four articulated podomeres. First podomere with two segmented spinneret (exopodite) on distal end. Second podomere half as long as first podomere, with bunch of fine setae along middle of anterior margin and one medium seta on postero-distal end. Third podomere eight-thirds as long as second podomere, with numerous fine setae along antero-proximal margin, medium setae on middle of anterior margin and on middle of posterior margin, respectively, and one medium setulous seta on postero-distal end. Fifth podomere quarter length of fourth podomere, with numerous fine setae on distal margin and one stout claw on distal end.  Mandibula (Fig. 4C1, C2). Coxa (Fig. 4C1) elongated, with one medium seta on antero-ventral part. Six coxal endites. Palp (Fig. 4C2) consisting of four articulated podomeres. First podomere (basis) with bifurcated lamella (exopodite) on middle of dorsal margin. Second podomere two-thirds as long as first podomere, with three medium setae on ventro-distal end. Third podomere five-fourths as long as second podomere, with one stout medium seta on outside of distal end and one medium seta on ventro-distal end. Fourth podomere two-fifths as long as third podomere, with four setae on distal end.  Maxillula (Fig. 4D and E). Thin branchial plate (exopodite; Fig. 4E) with approximately nine plumose setae. Basal podomere with one palp and three endites (Fig. 4D). Palp consisting of two articulated podomeres: first podomere with one long and one medium seta on antero-distal end; second podomere eleven-tenth as long as first podomere, with one medium seta on middle of posterior margin and two medium setae on distal end. Endites with three setae, respectively.  Fifth limb (Fig. 4F). Four articulated podomeres. First podomere with two short setae on antero-distal end. Second podomere five-sixths as long as first podomere, with one medium seta on antero-distal end. Third podomere four-fifths as long as second podomere. Fourth podomere three-halves as long as third podomere, with stout distal claw.  Sixth limb (Fig. 4G). Four articulated podomeres. First podomere with one short seta on antero-distal end. Second podomere four-fifth as long as first podomere, with one long seta on antero-distal end. Third podomere as long as second podomere. Fourth podomere seven-fifth as long as third podomere with stout distal claw.  Seventh limb. Absent.  Male copulatory organ (Fig. 5). Asymmetric. Right organ (Fig. 5B) smaller than left (Fig. 5A), with reduced components: square capsule with weakened framework; copulatory duct (Cd) extremely reduced; distal lobe (Dl) thin and crescent-shaped with thick seta on proximal part. Left organ bearing well-developed long copulatory duct (Cd) single coiled in distal part; short and stout claw-like dorsal ramus (Dr); two-pronged ventral ramus (Vr); and crescent-shaped distal lobe (Dl) with thick seta on centre of proximal part.  Genitalia of female (Fig. 6). Almost symmetric and consisting of rounded frame-work and winding duct with vesicle-like joint nearby opening. Duct opening on ventral side.  Eye. Absent.

Trusted

Creative Commons Attribution 3.0 (CC BY 3.0)

© Ryouichi Higashi, Akira Tsukagoshi

Source: ZooKeys

Belongs to 0 communities

This taxon hasn't been featured in any communities yet.

Learn more about Communities

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!