Dactylokepon holthuisi Bourdon, 1967

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 : 2068-2072

Dactylokepon holthuisi Bourdon, 1967

( Figures 3 , 4 )

Dactylecepon holthuisi Bourdon 1967, p 167 –174, Figures 1–3 . [Type locality: Akaba Gulf; infesting Eduarctus lewinsohni (Holthuis) ].

Material examined

Infesting Eduarctus martensii (Pfeffer) . South Sea, Stn 6059, 21 ° 309N, 113 ° 459E, 44.5 m, 10 January 1960, Guangzong Wu coll., 2♀, 2 „, CIEE605901 . Stn 6059, 21 ° 309N, 113 ° 459E, 45 m, 9 April 1959, Weiquan Zhang coll., dredge; 3♀, 1 „, CIEE605902 . Stn 6059, 21 ° 309N, 113 ° 459E, 45 m, 9 April 1959, Weiquan Zhang coll., dredge; 3♀, 1 „, CIEE605903 . Stn 6059, 21 ° 309N, 113 ° 459E, 38 m, 17 March 1959, Weiquan Zhang coll.; 5♀, 3 „, CIEE605904 . Stn 6063, 21 ° 309N, 113 ° 309E, 39.5 m, 16 February 1960, Shoupeng Shen coll., dredge; 5♀, 2 „, CIEE606301 . Stn 6063, 21 ° 309N, 113 ° 309E, 39.5 m, 15 July 1959, Xiutong Ma coll., dredge; 3♀, 3 „, CIEE606302 . Stn 6046, 21 ° 309N, 114 ° 309E, 74.5 m, 8 April 1959, Guangzong Wu coll., dredge; 3♀, 3 „, CIEE604601 . Stn 6065, 21 ° 009N, 113 ° 309E, 74 m, 17 February 1960, Jingzuo Qu coll., dredge; 5♀, 4 „, CIEE606501 . Stn 6065, 21 ° 009N, 113 ° 309E, 74 m, 14 July 1959, Xiutong Ma coll., 1♀, CIEE606502 . Stn 6065, 21 ° 009N, 113 ° 309E, 69 m, 9 April 1960, Zhican Tang coll., 1♀, CIEE606503 . Stn 6076, 21 ° 159N, 113 ° 009E, 45 m, 7 April 1960, Zhican Tang coll., dredge; 3♀, 2 „, 1♀ immature, CIEE607601 . Stn 6076, 21 ° 159N, 113 ° 009E, 43 m, 16 February 1959, Guansheng Liang coll.; 1♀, CIEE607602 . Stn 6052, 21 ° 309N, 114 ° 009E, 48 m, 17 March 1959; 3♀, 1 „, CIEE605201 . Stn 6091, 20 ° 309N, 112 ° 309E, 99.5 m, 6 April 1960, Zhican Tang coll., 1♀, CIEE609101 . Stn 6064, 21 ° 159N, 113 ° 309E, 52 m, 18 October 1959, Jieshan Xu coll., 1♀, CIEE606401 . Stn 6024, 20 ° 309N, 116 ° 009E, 45 m, 14 May 1960, Shoupeng Shen coll., 1♀ immature, 1 „, CIEE602401 . Stn 6132, 19 ° 459N, 110 ° 109E, 70 m, 28 January 1959, Yongliang Wang coll., 2♀, 1 „, CIEE613201 . Stn 6132, 19 ° 459N, 111 ° 159E, 73 m, 29 October 1959, Zhican Tang coll., 1♀ immature, CIEE613202 . Stn 6020, 22 ° 309N, 116 ° 009E, 38 m, 5 April 1959, Weiquan Zhang coll., 1♀, CIEE602001 . Stn 6020, 22 ° 309N, 116 ° 009E, 41 m, 25 January 1959, Weiquan Zhang coll., 1♀, CIEE602002 . Stn 6020, 22 ° 309N, 116 ° 009E, 37.7 m, 23 December 1959, Weiquan Zhang coll.; 1♀, CIEE602003 . Stn 6066, 20 ° 309N, 113 ° 309E, 88 m, 17 February 1960, Jingzuo Qu coll., dredge; 1♀, CIEE606601 . Stn 6023, 21 ° 459N, 116 ° 009E, 98.8 m, 23 April 1960, Jingzuo Qu coll., 1♀, CIEE602301 . Stn 6054, 21 ° 009N, 114 ° 009E, 79 m, 11 January 1960, Guangzong Wu coll., 1♀, 1 „, CIEE605401 . Stn 6154, 19 ° 159N, 110 ° 459E, 36 m, 6 May 1960, Jixin Liu coll., 1♀, 1 „, CIEE615401 . Stn 6027, 22 ° 159N, 115 ° 309E, 49 m, 9 December 1959, Weiquan Zhang coll., 1♀ immature, CIEE602701 .

Redescription of reference female

Length 4.46 mm (excluding uropods), maximal width 2.36 mm, head length 0.59 mm, head width 1.02 mm. Body distorted, 20 ° with right side convex (dextrally deflexed) ( Figure 3A ).

Head slightly bilobate, with narrow frontal lamina. Eyes absent ( Figure 3A ). Antenna of five articles, antennule of three articles. Maxilliped ( Figure 3B ) nearly triangular, its anterior article much longer, with prominent non-articulating, curved, and non-setose pointed palp; plectron short, pointed. Barbula ( Figure 3C ) with two projections on each side, inner pair with smooth margins, outer pair with slightly uneven margins, outer pair larger than inner pair.

Pereon broadest across third or fourth pereomere. No middorsal projections. Brood pouch almost covered by oostegites. First oostegite ( Figure 3D, E ) smoothly rounded anteriorly, produced into truncate extended point posterolaterally; posterior edge with a notch and setae; internal ridge smooth. Second pereomere 2 and left side of third pereomere with tubercles in a row. Pereopods almost similar, except progressively longer posteriorly.

Pleon of six pleomeres, first five bearing digitate lateral plates and biramous pleopods, terminal pleomere with long uniramous uropods. Lateral plates and biramous pleopods similar and simply digitate ( Figure 3F ). Uniramous uropods approximately three times longer than lateral plates ( Figure 3G ).

Description of juvenile female

All body segments distinct ( Figure 3H ). Eyes near anterolateral corners, prominent. Antennae extend beyond anterior edge of head. Pereon with nearly parallel sides, dorsolateral boss and tergal projection absent. First five pleomeres with lateral plates and biramous pleopods similar and slightly digitate. Uniramous uropods about twice longer than lateral plates of pleomere 5.

Redescription of reference male

Length 1.91 mm, maximal width across fifth pereomere, 0.48 mm, head length 0.24 mm, pleonal length 0.47 mm. Body gradually tapered posteriorly, all segments distinct ( Figures 3I , 4A ).

Head quadrate, broader than long, large dark eyes near posterior edge. Head distinctly separated from first pereomere ( Figure 3I ). Antenna of five articles, antennule of three articles, distally setose ( Figure 4B ).

Pereomeres deeply separated by anterolateral notches; small irregular pigmented spot on second to seventh pereomeres, or absent ( Figure 3I, J ). Prominent midventral tubercle on each pereomere. Pereopods all about same size, but first two pairs slightly larger than others ( Figure 4C, D ). Cutting edges of propodi, carpi, meri, and ischia setose.

Pleon of six segments without midventral tubercles, first five with tuberculiform pleopods, final pleomere bifurcate with setae on posterior margin ( Figure 4E ).

Remarks

This species was originally described under the name Dactylocepon holthuisi as a parasite of Scyllarus lewinsohni Holthuis by Bourdon (1967). Holthuis (2002) established a new combination for the host name, designating it Eduarctus lewinsohni (Holthuis) . This is the second record of this species; China is a new locality for D. holthuisi, Bourdon, 1967 , and the host Eduarctus martensii (Pfeffer) is recorded for the first time bearing bopyrid isopods.

Distribution and hosts

Gulf of Aqaba, Red Sea, Israel, on Eduarctus lewinsohni (Holthuis) ; South Sea, China, on Eduarctus martensii (Pfeffer) .

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 3. Dactylokepon holthuisi Bourdon, 1967. (A–H) Reference female: (A) dorsal view; (B) right maxilliped, external view; (C) barbula (left side); (D) right oostegite 1, external view; (E) right oostegite 1, internal view; (F) left pleopod 1; (G) uropod; (H) immature female (no. CIEE602701). (I, J) Reference male: (I) dorsal view of reference male (no.CIEE605901); (J) dorsal view of another male (no.CIEE605401). Scale bar: 1 mm (A); 0.73 mm (B–G); 0.86 mm (H); 0.40 mm (I); 0.44 mm (J).

Figure 4. Dactylokepon holthuisi Bourdon, 1967, reference male, SEM micrographs. (A) Ventral view; (B) right antennae; (C) pereopods 1–2, left side; (D) pereopods 3–4, left side; (E) ventral view of posterior pleomeres 5–6. Scale bars: 1 mm (A); 100 Mm (B–E).