Pandaridae Milne-Edwards, 1840

Venmathi Maran, B. A., Ohtsuka, Susumu & Shang, Xu, 2012, Records of Adult Caligiform Copepods (Crustacea: Copepoda: Siphonostomatoida) in Marine Plankton from East Asia, Including Descriptions of Two New Species of Caligus (Caligidae), Species Diversity 17 (2), pp. 201-219 : 213-216

Family Pandaridae Milne-Edwards, 1840 Pandarus satyrus Dana, 1852

( Figs. 10 , 11 )

Pandarus satyrus Dana, 1852: 1368 ; Brady 1883: 134; Bassett-Smith 1899: 467; Wilson 1907: 415; 1914: 71; Yamaguti 1936: 5; Bere 1936: 595; Shiino 1957: 364, 1959a: 315, 1959b: 352, 1960: 493; Ho 1963: 90; Cressey 1967: 15; Benz 1981: 966.

Material examined. One young male (KMNH IvR 500,509), off Akuseki Island, Tokara Islands, Kagoshima Prefecture, Japan (St. 7), 27 May 2008 ( Table 1) .

Description. Male. Body ( Fig. 10A ) 6.31 mm long, excluding caudal setae. Cephalothorax narrow, longer than wide, 4.00× 2.87 mm. Second pediger extended posterolaterally into pair of lobe-like structures. Genital complex wider than long, 1.23× 1.50 mm. Abdomen small, wider than long, 0.36× 0.76 mm. Caudal ramus small and wide, 0.28× 0.32 mm, armed with 4 long and 2 small setae.

Antennule ( Fig. 10B ) 2-segmented; proximal segment long with 9 plumose and 5 hirsute setae; distal segment small with 5 long, hirsute setae and 3 short setae. Antenna ( Fig. 10C ) indistinctly 3-segmented; proximal segment unarmed; middle segment unarmed, lacking posterior process; distal segment with curved claw bearing 1 proximal and 1 medial seta. Post-antennal process ( Fig. 10C ) large, modified as adhesion pad, bearing 2 basal papillae on sternum with 4 setules each. Maxillule ( Fig. 10C ) represented by small, rounded process with 2 small setae. Oral cone ( Fig. 10D ) long; 2 large adhesion pads present on ventral surface of cephalothorax lateral to oral cone. Mandible ( Fig. 10E ) slender, with 10 marginal teeth subapically. Maxilla ( Fig. 10F ) 2-segmented; proximal segment robust; distal segment broad, with 2 broad claws ornamented with hyaline membrane distally and patchy spinules at base. Maxilliped ( Fig. 10G ) incompletely 3-segmented; proximal segment largest; middle segment small, partly fused with distal segment to form subchela; distal segment short, robust, pointed claw armed with 2 setae subterminally. Sternal furca absent.

Armature on rami of legs 1-4 summarized in Table 4.

Leg 1 ( Fig. 11A ) protopod with basis bearing 1 outer and 1 inner plumose seta; exopod 2-segmented, distal segment bearing 3 long, thick plumose setae; endopod 2-segmented, distal segment carrying 3 long, thick plumose setae. Leg 2 ( Fig. 11B ) protopod with basis bearing small outer and long, plumose inner setae; exopod 2-segmented; distal segment carrying 3 small spines and 5 long setae; endopod 2-segmented, bearing 7 setae distally. Leg 3 ( Fig. 11C ) protopod with basis bearing 1 outer and 1 inner plumose seta; exopod 2-segmented, proximal segment with small spine; distal segment carrying 2 small and 1 long spines. Leg 4 ( Fig. 11D ) protopod with basis bearing outer plumose seta; exopod 1-segmented with 3 small and 1 long spines and fringed with hyaline membrane laterally. Leg 5 ( Fig. 11E ) represented by papilla bearing 1 plumose and 1 pinnate seta.

Remarks. Adults of P. satyrus differ from the present young male in the following characters: (1) the 2-segmented abdomen (vs non-segmented), and (2) the setal formula of the second, third, and fourth legs (vs fewer elements) (cf. Shiino 1954b). In our previous study, we collected many chalimus stages and adult males of Pandarus sp. in plankton samples from Japan ( Venmathi Maran and Ohtsuka 2008). Pandarus is host-specific to elasmobranchs ( Cressey 1967; Benz 1981, 1992). Normally they would be firmly attached by their maxillipeds to the body surface of sharks ( Benz 1981, 1992; Benz et al. 2003), but if accidentally detached they can become planktonic ( Venmathi Maran and Ohtsuka 2008). A separate genus Nogaus Leach, 1816 (or Nogagus ), was established for free-swimming specimens in the family Pandaridae by Kabata (1979), but still several nominal species of Nogaus have yet to be assigned to a valid genus (cf. Boxshall and Halsey 2004).

Distribution. Shiino (1954b) found both sexes of P. satyrus on the body surface of the smooth hammerhead shark Sphyrna zygaena (Linnaeus, 1758) and the blue shark Prionace (= Isuropis) glauca (Linnaeus, 1758) in Japanese waters. Pandarus satyrus is cosmopolitan, recorded from the Atlantic coast of the United States ( Wilson 1914), Japan ( Shiino 1954b, 1959a, b, 1960), the Gulf of Mexico, and the Indo- Pacific and Atlantic Oceans ( Cressey 1967).

Figures

Fig. 10. Pandarus satyrus Dana, 1852, young male (KMNH IvR 500,509). A, habitus; B, antennule; C, antenna, post-oral process, and maxillule; D, oral cone; E, mandible; F, maxilla; G, maxilliped. Scale bars:2.5mm (A), 0.1mm (B–G), 0.2mm (D), 0.05mm (E).

Fig. 11. Pandarus satyrus Dana, 1852, young male (KMNH IvR 500,509). A, leg 1; B, leg 2; C, leg 3; D, leg 4; E, leg 5. Scale bars: 0.1mm (A–E).