Splanchnotrophus Hancock & Norman 1863

Figure 1.Live coloration of the host nudibranchs and the splanchnotrophids. A Hypselodoris festiva infected by an ovigerous specimenof Certosomicola japonica sp. n. B an egg sac of Ceratosomicola japonica sp. n. and the gill circle of Hypselodoris festiva with the mantle malformed into an elongate tube C Thecacera pennigera infected by an ovigerous specimen of Splanchnotrophus helianthus sp. n. D Trapania pennigera with the mantle removed to show a female specimen of Splanchnotrophus helianthus on the visceral sac E Trapania miltabrancha infected by an ovigerous specimen of Splanchnotrophus imagawai sp. n (photo by K. Imagawa) F gill circle of Trapania miltabrancha with egg sacs of Splanchnotrophus imagawai sp. n. (photo by K. Imagawa) G Roboastra luteolineata infected by an ovigerous specimen of Majimun shirakawai gen. et sp. n. (photo by N. Shirakawa) H female Majimun shirakawai gen. et sp. n. with dwarf male attached to the posterior part of the body. Scale bars = 5 mm in A; 1 mm in B, D, H.

Figure 5.Splanchnotrophus helianthus sp. n., female, holotype NSMT–Cr 22244. A habitus, dorsal A’ enlarged view of egg sac B habitus, ventral, p1 = leg 1, p2 = leg 2 C posterior portion of body, ventral, p3 = leg 3 D fourth pedigerous somite and genito-abdomen, ventral E caudal ramus, dorsal F cephalosome, ventral. Scale bars = 1 mm in A; 100 μm in A’; 500 μm in B; 200 μm in C, F; 100 μm in D; 20 μm in E.

Figure 6.Splanchnotrophus helianthus sp. n., female, holotype NSMT–Cr 22244. A antennule, anterior B oral area C mandible, posterior D maxilla E leg 1 F leg 2 G leg 3. Scale bars = 20 μm in A, E, F; 30 μm in B; 10 μm in C, D, G.

Figure 7.Splanchnotrophus helianthus sp. n., male, allotype NSMT–Cr 22245. A habitus, dorsal B habitus, ventral C habitus, lateral D free thoracic somites and abdomen, ventral E caudal ramus, ventral F oral area G leg 1 H leg 2. Scale bars = 100 μm in A, B, C; 50 μm in D; 20 μm in E.

Figure 1.Live coloration of the host nudibranchs and the splanchnotrophids. A Hypselodoris festiva infected by an ovigerous specimenof Certosomicola japonica sp. n. B an egg sac of Ceratosomicola japonica sp. n. and the gill circle of Hypselodoris festiva with the mantle malformed into an elongate tube C Thecacera pennigera infected by an ovigerous specimen of Splanchnotrophus helianthus sp. n. D Trapania pennigera with the mantle removed to show a female specimen of Splanchnotrophus helianthus on the visceral sac E Trapania miltabrancha infected by an ovigerous specimen of Splanchnotrophus imagawai sp. n (photo by K. Imagawa) F gill circle of Trapania miltabrancha with egg sacs of Splanchnotrophus imagawai sp. n. (photo by K. Imagawa) G Roboastra luteolineata infected by an ovigerous specimen of Majimun shirakawai gen. et sp. n. (photo by N. Shirakawa) H female Majimun shirakawai gen. et sp. n. with dwarf male attached to the posterior part of the body. Scale bars = 5 mm in A; 1 mm in B, D, H.

Figure 8.Splanchnotrophus imagawai sp. n., female, holotype NSMT–Cr 22249. A habitus, dorsal B habitus, ventral, p1 = leg 1, p2 = leg 2 C posterior portion of body, ventral, p3 = leg 3 D fourth pedigerous somite and genito-abdomen, ventral E caudal ramus, ventral F egg sac. Scale bars = 1 mm in A; 500 μm in B, F; 200 μm in C; 100 μm in D; 20 μm in E.

Figure 9.Splanchnotrophus imagawai sp. n., female, holotype NSMT–Cr 22249. A anterior portion of cephalosome B antennule, ventral C oral area D mandible, posterior E maxilla F leg 1 G leg 2 H leg 3. Scale bars = 100 μm in A; 50 μm in B, C; 10 μm in D, H; 20 μm in E, F, G.