Cymadusa filosa Savigny, 1816

Thacker, Dimple, Myers, Alan & Trivedi, Jigneshkumar, 2023, A new species and a new record of the amphipod genus Cymadusa Savigny, 1816 (Senticaudata, Ampithoidae) from India, Zootaxa 5297 (3), pp. 393-405 : 398-402

Cymadusa filosa Savigny, 1816

( Figs 5–8 )

Cymadusa filosa Savigny, 1816: 51 , 109, pl. IV, figure 1a, b, e, i, o, u; Monod, 1971: 176–184, figures 66–78; Krapp-Schickel, 1982: 106–108, figures 71, 72, key; Ledoyer, 1982: 130–135, figures 44–46; Ledoyer, 1984: 15–18, figures 5, 6; Lyons &

Myers, 1990: 1203, figures 7, 8; Peart, 2004: 304-310, figures 1-4.

Ampithoe filosa Audouin, 1826 : pt 4: 93, pl. XI, figures 4, 5.

Grubia hirsuta Chevreux, 1900: 95–101 , figures 1–5; Chevreux & Fage, 1925: 339–340, figure 347; Schellenberg, 1925: 186–187.

Grubia coei Kunkel, 1910: 97 , figure 38.

Grubia filosa Ruffo, 1938: 147 , 172; Ruffo, 1947: 169–173, figures 1–3; Ruffo, 1959: 19; Ruffo, 1969: 62–63; Oliveira, 1953: 358–364, figures 22, 23.

Grubia sardenta Oliveira, 1953: 365 , pls 25, 26.

Materials examined. Four males (8–13 mm); four females (8–10 mm), LFSC. ZRC –194, from algae growing on submerged rocks, Shivrajpur (22º19’53.4’’N 68º56’59.6’’E), Gujarat State, India, 28 February 2022, coll. D. R. Thacker .

Description. Based on male, 13 mm.

Head: Eyes medium. Antenna 1 longer than antenna 2; peduncular article 1 subequal to article 2; article 3 shorter than article 1 and 2; accessory flagellum 2 articulated. Antenna 2 densely setose on lateral margins.

Pereon: Gnathopod 1 smaller than gnathopods 2, poorly setose; coxa with straight anterior margin, ventral margin having oval anterior corner with long setae; basis longer than coxa, distal lobe present; ischium small; merus produced into long, acute, conical anteroventral lobe; carpus longer than merus and propodus, subequal to basis, longer than propodus; propodus oval with straight palm; dactylus as long as palm. Gnathopod 2 larger than gnathopods 1, lateral margins with long dense plumose setae; coxa with round corners and setose ventral margin; basis longer than coxa, distal lobe present; ischium small and rectangular; merus formed into small, subacute, anteroventral lobe; carpus longer than merus, shorter than propodus; propodus large, subquadrate; palm straight with small, posterodistal tooth, mid-palmar tooth absent; dactylus subequal to palm.

Pleon: Uropod 1 peduncle with 13 robust setae; endopodite longer than exopodite. Uropod 2 endopodite longer than exopodite. Uropod 3 exopodite subequal to endopodite with both hooks curved; lateral margin with setal fringe; apical setae present on endopodite. Telson fleshy, somewhat triangular with lateral and apical setal fringe.

Distribution. Mediterranean Sea ( Peart, 2004), Brazil ( Andrade & Senna, 2017), India (present study).

Remarks. The specimen examined in the present study agrees with the description given by Peart (2004) in having the male gnathopod 2 lateral margins with long dense plumose setae and the propodus palm being straight with a small, posterodistal tooth, lacking a mid-palmar spine.

Figures

FIGURE 5. Cymadusa filosa Savigny, 1816 (LFSC ZRC-194), (a) male, 13 mm; (b) female, 10 mm, Shivrajpur, Gujarat, India. Scale bars—1 mm.

FIGURE 6. Cymadusa filosa Savigny, 1816 (LFSC ZRC-194), male 13 mm, Shivrajpur, Gujarat, India. Scale bars—0.5 mm.

FIGURE 7. Cymadusa filosa Savigny, 1816 (LFSC ZRC-194), male 13 mm, Shivrajpur, Gujarat, India. Scale bars—1.0 mm.

FIGURE 8. Cymadusa filosa Savigny, 1816 (LFSC ZRC-194), female 10 mm, Shivrajpur, Gujarat, India. Scale bars—1.0 mm.