Georissus (Nipponogeorissus) granulosus Satô, 1972

Yasuda, Kohei & Yoshitomi, Hiroyuki, 2022, Revision of the genus Georissus (Coleoptera, Hydrophiloidea, Georissidae) of Japan, European Journal of Taxonomy 817 (1), pp. 111-142 : 121-123

Georissus (Nipponogeorissus) granulosus Satô, 1972

[Japanese name: Sesuji-marudoromushi]

Figs 2C , 3B, H , 4B, E, H–I, N , 5C , 6C , 7C , 8C , 9C ; Table 1

Georissus (Nipponogeorissus) granulosus Satô, 1972: 212 .

Georissus (Nipponogeorissus) granulosus – Satô 1981: 4; 1985: 205. — Hansen 1999: 49. Diagnosis

This species is easily distinguished from other Japanese species of Georissus by the granulated pronotum and shape of male aedeagus; shape elongated and narrow, phallobase widening. This species is distinguished from Georissus biroi described from Papua New Guinea by the carinae of frons; G. granulosus has transverse carinae, in contrast to their absence in G. biroi .

Material examined

Holotype JAPAN – Honshu : Mie Pref. • ♀; Tsu-shi , Furukawa ; 23 Aug. 1958; H. Ichihashi leg.; EUMJ ( Fig. 3B, L ).

Other material JAPAN – Honshu : Mie Pref. • 5 ex.; Ise-shi, Iso-cho, Miya-gawa ; 16 Jun. 2008; K. Akita leg.; EUMJ .

Redescription

COLORATION ( Fig. 2C ). Black, mat, legs dark reddish brown.

HEAD ( Fig. 6C ). Clypeus uneven, provided with foveae and carinae throughout; slr, consisted of granules, connecting to smb at median portion; smb nonsequential, connecting each other, forming oblong oval; lsa connecting each other, forming U-shape.

PRONOTUM ( Fig. 7C ). Relatively large, widest at the middle. Pronotal disc provided with granules densely. Anterior portion provided with indistinct granules extensively; anterior margin smooth, not crenelated; smlg distinct, with longitudinal row of pits. Posterior portion slightly convex than anterior potion, bearing granulation regularly; lateral margins protruding; slb developed; pg indistinct, short.

ELYTRA. Entirely granulate. Elytral intervals 2, 4, 6 and 8 elevated, forming longitudinal carinae. Humeral bulge distinct, bearing granules. Lateral ridges indistinct. Hind wings developed.

ABDOMEN ( Fig. 8C ). Lateral margin of ventrites uniformly narrowing posteriorly. Ventrite 1 with large granules extensively. Granulation of ventrites 2–5 large and relatively indistinct.

MALE GENITALIA ( Fig. 9C ). Aedeagus 0.37 mm long. Parameres slightly shorter than phallobase, basal portions of parameres combined as wide as anterior portion of phallobase; lateral margins. Median lobe shorter than parameres, subparallel-sided, slightly angular at apex; basal struts short. Phallobase about 2.4 times as long as wide, widening posteriorly; posterior portion with large basal foramen.

FEMALE GENITALIA. Not examined.

Biological notes

This species inhabits tidal flats that are submerged at high tide ( Akita 2008). The holotype was collected at light ( Satô 1981).

Distribution

Japan: Honshu (Mie Pref.) ( Fig. 13 ).

Figures

Fig. 2. Dorsal view of Georissus spp. A. G. (G.) canalifer Sharp, 1888. B. G. (G.) babai Satô, 1970. C. G. (Ni.) granulosus Satô, 1972. D. G. (Ne.) japonicus Satô, 1972. E. G. (Ne.) kurosawai Nakane, 1963. F. G. (Ne.) takahashii sp. nov., holotype, ♂ (EUMJ). G. G. (Ne.) satoi sp. nov., holotype (EUMJ). Scale bars = 0.5 mm.

Fig. 3. Holotypes of Georissus spp. A–F. Dorsal habitus. G–L. Labels. A, K. G. (G.) babai Satô, 1970, ♂ (EUMJ). B, L. G. (Ni.) granulosus Satô, 1972, ♀ (EUMJ). C, H. G. (Ne.) kurosawai Nakane, 1963, ♂ (SEHU). D, J. G. (Ne.) japonicus Satô, 1972, ♂ (EUMJ). E, G. G. (Ne.) sakaii Satô, 1972, ♂ (EUMJ). F, I. G. (Ne.) katsuoi Nakane, 1995 (SEHU). Scale bars = 0.5 mm.

Fig. 4. Mouth parts and antennae of Georissus spp. A–C. Left maxillae. D–F. Labrum. G–I. Labial palpi. J–L. Left mandibles. M–O. Left antennae. A, D, G, J, M. G. (G.) canalifer Sharp, 1888. B, E, H, K, N. G. (Ni.) granulosus Satô, 1972. C, F, I, L, O. G. (Ne.) japonicus Satô, 1972. Scale bars = 0.1 mm.

Fig. 5. Dorsal habitus of Georissus spp. A. G. (G.) canalifer Sharp, 1888. B. G. (G.) babai Satô, 1970. C. G. (Ni.) granulosus Satô, 1972. D. G. (Ne.) japonicus Satô, 1972. E–F. G. (Ne.) kurosawai Nakane, 1963 from Hokkaido (E) and Nagano (F). G–H. G. (Ne.) takahashii sp. nov. from Kochi (G) and Okinawa (H). I. G. (Ne.) satoi sp. nov.

Fig. 6. Head of Georissus spp. A. G. (G.) canalifer Sharp, 1888. B. G. (G.) babai Satô, 1970. C. G. (Ni.) granulosus Satô, 1972. D. G. (Ne.) japonicus Satô, 1972. E–F. G. (Ne.) kurosawai Nakane, 1963 from Hokkaido (E) and Nagano (F). G–H. G. (Ne.) takahashii sp. nov. from Kochi (G) and Okinawa (H). I. G. (Ne.) satoi sp. nov.

Fig. 7. Pronotum of Georissus spp. A. G. (G.) canalifer Sharp, 1888. B. G. (G.) babai Satô, 1970. C. G. (Ni.) granulosus Satô, 1972. D. G. (Ne.) japonicus Satô, 1972. E–F. G. (Ne.) kurosawai Nakane, 1963 from Hokkaido (E) and Nagano (F). G–H. G. (Ne.) takahashii sp. nov. from Kochi (G) and Okinawa (H). I. G. (Ne.) satoi sp. nov.

Fig. 8. Ventrites of Georissus spp. A. G. (G.) canalifer Sharp, 1888. B. G. (G.) babai Satô, 1970. C. G. (Ni.) granulosus Satô, 1972. D. G. (Ne.) japonicus Satô, 1972. E–F. G. (Ne.) kurosawai Nakane, 1963 from Hokkaido (E) and Nagano (F). G–H. G. (Ne.) takahashii sp. nov. from Kochi (G) and Okinawa (F). I. G. (Ne.) satoi sp. nov. Abbreviation: vt = ventral teeth. Scale bars = 100 μm.

Fig. 9. Male aedeagus of Georissus spp. A. G. (G.) canalifer Sharp, 1888. B. G. (G.) babai Satô, 1970. C. G. (Ni.) granulosus Satô, 1972. D. G. (Ne.) japonicus Satô, 1972. E. G. (Ne.) kurosawai Nakane, 1963. F–G. G. (Ne.) takahashii sp. nov. from Kochi (F) and Okinawa (G). H. G. (Ne.) satoi sp. nov. Scale bar = 0.1 mm.

Fig. 13. Distribution map of Georissus spp. Russian localities for Georissus (G.) canalifer Sharp, 1888 and G. (Ne.) japonicus Satô, 1972 are omitted.

Tables

Table 1. Measurements of Georissus (G.) spp. and G. (Nipponogeorissus) granulosus Satô, 1972.

G. (G.) canalifer (N = 53)	G. (G.) babai (N = 20)	G. (Ni.) granulosus (N = 5)
TL (mm)	1.46–2.30 (1.91)	1.34–1.90 (1.91)	1.28–1.54 (1.38)
EL (mm)	0.86–1.62 (1.27)	0.82–1.26 (1.09)	0.86–1.02 (0.92)
EW (mm)	0.90–1.38 (1.17)	0.82–1.16 (1.05)	0.70–0.88 (0.79)
PL (mm)	0.52–0.78 (0.64)	0.52–0.66 (0.60)	0.40–0.52 (0.46)
PW (mm)	0.70–1.04 (0.85)	0.68–0.88 (0.79)	0.52–0.62 (0.58)
PW/PL	1.08–1.66 (1.33)	1.15–1.41 (1.32)	1.15–1.35 (1.26)
EL/EW	0.86–1.23 (1.08)	0.83–1.24 (1.03)	1.05–1.26 (1.16)
EL/PL	1.43–2.48 (1.98)	1.58–2.07 (1.82)	1.87–2.20 (2.00)
EW/PW	1.10–1.56 (1.38)	1.21–1.53 (1.33)	1.28–1.47 (1.37)
TL/EW	1.45–1.84 (1.64)	1.34–1.86 (1.60)	1.57–1.83 (1.74)