Dactylokepon richardsonae Stebbing, 1910

An, Jianmei, Yu, Haiyan & Williams, Jason D., 2007, Four new records and a new species of Dactylokepon Stebbing, 1910 (Epicaridea: Bopyridae: Ioninae) from Chinese waters, Journal of Natural History 41 (33 - 36), pp. 2063-2079 : 2064-2066

Dactylokepon richardsonae Stebbing, 1910

( Figure 1 )

Dactylokepon richardsonae Stebbing 1910, p 85 , 113, Plate 11C [Type locality: Seychelle Islands; infesting Trapezicepon cymodoce (Herbst) ]; Nierstrasz and Brender à Brandis 1923, p 83; Shiino 1942, p 444, 447; Markham 1975, p 61, 64, 66, Table 1; 1991, p 289, 291, 292, 294, 296, 297, Figure 2 [Bangkok, Thailand, infesting Portunus tuberculosus (A. Milne Edwards) ].

Dactylecepon richardsonae: Bourdon 1967, p 122 ; 1980, p 243; 1983, p 855–857, 859, Figure 7 [Marsegu Island, Moluccas; infesting T. cymodoce ]

Material examined

Infesting Portunus argentatus (White) . Nansha, Stn 64, 4 ° 009N, 112 ° 069E, 56 m, 1 August 1988, dredge; 2♀, CIEP6401 , 2 „, CIEP6402 . Nansha, Stn 39, 7 ° 299N, 114 ° 309E, 46 m, 13 May 1987, dredge; 3♀, 3 „, CIEP3901 (one female immature) .

Remarks

The first description of Dactylokepon richardsonae by Stebbing (1910) was so brief that it became difficult to be certain of the identification of subsequent specimens. However, Bourdon (1983) and Markham (1991) redescribed the species in great detail. The female specimens ( Figure 1A–H ) conform well to Markham’s description (1991). However, there are some minor differences, such as tubercules on tergal projections of pereomere 2 ( Figure 1A ); basal segment of antennae 2 not as prominent as in Markham’s specimen (1991) ( Figure 1C ). Four males ( Figure 1I, J ) are similar to Bourdon’s description (1983), the final pleomere round and lacking posterolateral corners. Nevertheless another male ( Figure 1K ) attached to an immature female is similar to that of Markham (1991), the final pleomere truncate, with distinct posterolateral corners. The host species Portunus argentatus (White) is recorded for the first time bearing parasitic isopods, and this is the first record of D. richardsonae from Nansha, China.

Distribution and hosts

Seychelles, Indian Ocean, on Trapezia cymodoce (Herbst) ; Bangkok, Thailand, on Portunus tuberculosus (A. Milne Edwards) ; Nansha, China on Portunus argentatus (White) .

Figures

Figure 1. Dactylokepon richardsonae Stebbing, 1910. (A–H) Reference female: (A) dorsal view; (B) left antennule; (C) left antenna; (D) right maxilliped, external view; (E) barbula (left side); (F) left oostegite 1, external view; (G) left oostegite 1, internal view; (H) right pleopod 1. (I–K) Reference male: (I) dorsal view; (J) ventral view; (K) ventral view of pleomeres of another male (no. CIEP3901). Scale bar: 1 mm (A); 0.28 mm (B, C); 0.62 mm (D, F, G, H); 0.36 mm (E); 0.33 mm (I, J, K).

Figure 2. Dactylokepon semipennatus Bourdon, 1983. (A–F) Reference female: (A) dorsal view; (B) left antennae; (C) right maxilliped, external view; (D) barbula (left side); (E) left oostegite 1, external view; (F) left oostegite 1, internal view. (G–J) Reference male: (G) dorsal view; (H) ventral view; (I) left antennae; (J) left pereopod 1. Scale bar: 1 mm (A); 0.13 mm (B, I, J); 0.47 mm (C, D); 0.70 mm (E, F); 0.30 mm (G, H).

Figure 7. Dactylokepon barbuladigitus, new species, allotype, SEM micrographs. (A) Ventral view; (B) right antennae; (C) pereopods 1–3, left side; (D) ventral view of pleomere 6, showing small anal cone extending posteriorly between two lobes; (E) distal margin of lobe of pleomere 6. Scale bars: 1 mm (A); 100 mm (B–D); 10 mm (E).