Protozantaena Perkins, 1997

Perkins, Philip D., 2009, Revisions of the genera Parhydraena Orchymont, Protozantaena Perkins, Decarthrocerus Orchymont, and Parhydraenopsis nomen novum, aquatic and humicolous beetles from Africa and Madagascar, and comparative morphology of the tribe Parhydraenini (Coleoptera: Hydraenidae), Zootaxa 2038, pp. 1-119 : 41

Protozantaena Perkins, 1997

Protozantaena Perkins, 1997: 174 (type species Protozantaena labrata Perkins , by original designation).

Diagnosis. Recognized by the very small size (length ca. 1.35–1.75 mm); the rather flattened body form; the ten-articled antenna (five + club); the lack of an hypomeral carina; the hypomeral antennal pocket setae forming a strong cup; the weakly developed ocelli located between the midline and the eyes; and the transverse pronotum with anterior hyaline margin and lacking postocular emarginations. Distinguished from Parhydraena and Decarthrocerus by the lack of an hypomeral carina ( Fig. 3), and the very small size; further distinguished from Decarthrocerus by the markedly different habitus ( Fig. 1). Distinguished from Discozantaena by the very small size, the presence of hypomeral antennal pocket setae, and the markedly different habitus. Distinguished from Parhydraenopsis by the very small size, the less convex form, the different elytral puncture pattern, and the markedly different aedeagal form.

Description. Body size very small, length ca. 1.35–1.75 mm; form elongate oval, weakly to moderately transversely convex dorsally, head not deflexed. Antennomeres ten (five + club), second slightly longer than combined lengths of third to fifth. Maxillary palpus total length variable, length/head width ca. 0.41–0.72; ratios of articles two to four (last) variable, but fourth always longest and third always shortest (e.g., 4/2/7 and 6/5/10). Eyes well-developed, not elevated, 6–8 facets in longest series in dorsal aspect. Labrum set at an angle to clypeus, usually same length or slightly longer than clypeus, shape of anterior margin straight to emarginate. Clypeus anterior margin and frontoclypeal suture slightly arcuate. Ocelli weakly convex, located midway between midline and eyes. Frons very weakly convex between ocelli; area behind and between ocelli lacking carinae. Pronotum with anterior and posterior shallow transverse impressions on disc, posterior impression usually U-shaped; anterior hyaline border present over median third, extremely narrow. Hypomeron lacking carina at margin of hydrofuge pubescence; antennal pocket bordered by row contiguous, arcuate setae forming strong cup, numbering ca. 12–18. Proventral antennal cleaner, a dense cluster of sharp spines, located on anterolateral margin of each side of proventrite. Metaventrite with shallow impression on disc in basal 1/2, with midlongitudinal carina between impression and mesoventral intercoxal process. Elytra with ten rows of punctures, six between suture and humerus; serial punctures deeper and larger than punctures on intervals, setae slender and usually very short. Intercoxal sternite small, triangular. Aedeagus rather simplified, with gonopore at tip of long, rigid flagellum; parameres, when present, minute, each with two setae.