Cymadusa filosa Savigny, 1816

Peart, R. A., 2004, A revision of the Cymadusa filosa complex (Crustacea: Amphipoda: Corophioidea: Ampithoidae), Journal of Natural History 38 (3), pp. 301-336 : 304-310

Cymadusa filosa Savigny, 1816

(figures 1–4)

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 and Myers, 1990: 1203, figures 7, 8.

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

Grubia hirsuta Chevreux, 1900: 95–101 , figures 1–5; Chevreux and 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.

Cymadusa sardenta: Sivaprakasam, 1970: 153–156 , figure 13.

Type material. NEOTYPE: male, 16 mm length, MVR-Cr, Cargliari, Sardinia, Mediterranean Sea , 39°20∞N, 09°10∞E, 1939.

Type locality. Sardinia, Mediterranean Sea .

Material examined. Female (one specimen), Cesarea, Israel, Mediterranean Sea, 14 June 1952 , S. Ruffo; males and females (10 specimens), MVR-Cr, Mer de Boughrar , Tunisia, Mediterranean Sea, 37°15∞N, 09°50∞E, 8 September 1993 ; females (two specimens), MVR-Cr, Cargliari , Sardinia , Mediterranean Sea , 39°20∞N, 09°10∞E; males and females (four specimens), Gulf of Tunisia, Tunisia, Mediterranean Sea, 37°00∞N, 10°50∞E, 0.3– 2 m, 21 September 1914, collected by Scheicke.

Diagnosis. Antenna 1 with a two-articulate accessory flagellum. Antenna 2 densely setose (male). Gnathopod 1 poorly setose; merus produced to form a long, acute anteroventral lobe; carpus elongated, narrow and subrectangular. Gnathopod 2 with densely setose margins, propodal palm with posterodistal defining tooth small and acute, mid-palmar tooth absent; dactylus subequal to palm.

Description

Based on neotype, male, 16 mm length. Eye is black.

Head. Antenna 1 longer than antenna 2; peduncular article 1 subequal to article 2, article 2 longer than article 3, article 3 shorter than article 1; primary flagellum incomplete, at least 48 articles; accessory flagellum with two articles. Antenna 2 with dense, plumose setae on ventral margin; peduncular article 4 subequal to article 5. Lower lip outer plate, outer lobe longer than inner lobe. Mandible molar setal row on both mandibles with 11 plumose robust setae; left mandibular palp article 1 shorter than article 2, article 2 subequal to article 3, article 3 longer than article 1; long plumose setae on the apical margin; right mandibular palp twisted on slide during mounting. Maxilla 1 inner plate with six long slender plumose setae. Maxilliped strongly setose.

Pereon. Gnathopod 1 smaller than gnathopod 2; poorly setose with simple slender setae; coxa produced forward, anterior margin straight, ventral margin with long, plumose setal fringe; basis longer than the coxa, with long plumose setal fringe, distal lobe present; merus produced to form a long, acute anteroventral lobe; carpus longer than merus, longer than propodus, parallel margins at distal end, carpal lobe rounded; propodus ovoid; palm entire, straight, posterodistal tooth absent, midpalmar tooth absent; dactylus subequal to palm. Gnathopod 2 margins with long, plumose setae; coxa with long, plumose setal fringe on ventral margin; basis longer than coxa, with long plumose setae in a fringe, distal lobe absent; merus produced to form a small, subacute anteroventral lobe; carpus longer than merus, shorter than propodus; propodus subquadrate; palm entire, straight, posterodistal tooth subacute, small, mid-palmar tooth absent; dactylus subequal to palm, tapering evenly.

Pereopods 3 and 4 similar in shape; coxae with a dense, plumose setal fringe. Pereopod 5 coxae with setal fringe on ventral margin and on the medial surface. Pereopod 6 basis without medial setae. Pereopod 7 basis ovoid. Pereopods 6 and 7 much longer than pereopods 3–5; distal articles with dense setae.

Pleon. Epimeron 3 rounded, with a small subacute tooth. Uropod 1 with 13 peduncular robust setae; outer ramus shorter than inner ramus. Uropod 2 outer ramus slightly shorter than inner ramus. Uropod 3 with seven distal peduncular robust setae; outer ramus subequal to inner ramus, with both hooks weakly curved, setal fringe present on lateral margin; inner ramus with apical robust and slender setae. Telson rounded, apical slender setae in oblique rows, also with lateral setae, apical cusps present.

Female. Based on female, 17 mm length.

Head. Antenna 1 primary flagellum incomplete, at least 30 articles; Antenna 2 with sparse plumose setae on ventral margin.

Pereon. Gnathopod 1 subequal in size to gnathopod 2; poorly setose with simple, slender setae; coxae produced forward, anterior margin straight, ventral margin with simple setae of different lengths; basis subequal in length to coxa, with long plumose setal fringe, distal lobe present; merus produced to form a small subacute anteroventral lobe; carpus longer than merus, subequal in length to propodus, parallel margins at distal end, carpal lobe truncated, with rounded corners; propodus ovoid; palm entire, straight, posterodistal tooth absent, mid-palmar tooth absent; dactylus subequal to palm. Gnathopod 2 margins poorly setose, with simple setae; coxa with simple setae of different lengths, reaching two-thirds the length of the ventral margin; basis shorter than coxa, with sparse simple setae, distal lobe present; merus produced to form a small, subacute anteroventral lobe; carpus longer than merus, shorter than propodus; propodus subquadrate; palm entire, straight, posterodistal tooth subacute, small, mid-palmar tooth absent; dactylus subequal to palm.

Remarks

This specimen has been assigned as a neotype for a number of reasons. The type specimens of Savigny’s 1816 Cymadusa filosa are missing. The most likely repository for this material is the Muséum National d’Histoire Naturelle, Paris as Savigny was a naturalist with Napoleon’s army in northern Africa ( Fransen et al., 1997) and Audouin (the first reviewer of Savigny’s work in 1826), worked on Savigny’s material and published it while he was a curator at this museum ( Fransen et al., 1997). The specimens were not present at the museum in Paris when checked (DeFaye, personal communication). A number of other institutions were asked about the location of the type material, but none knew of their whereabouts or referred to the Muséum National d’Histoire Naturelle, Paris.

In assigning a neotype it is preferable to assign material which comes from as close to the type locality as possible ( International Commission on Zoological Nomenclature, 2000). The original specimens were collected in Egypt by Savigny (1816). This could mean either the Red Sea or the Mediterranean Sea as Savigny collected on both coasts. It was not possible for monetary reasons to go to Egypt and collect samples in search of that species. As there were a number of collections from the Mediterranean Sea which had been recorded in the literature, it was decided to use one of these. The material chosen is from Sardinia and the type locality is Egypt, both in the Mediterranean Sea. The specimen from Sardinia was assigned as the neotype because it fits what description we have of the original material and is complete and in good condition.

Grubia hirsuta Chevreux, 1900 was considered as a possible source of material for redescribing C. filosa . Grubia hirsuta was recorded from Tunisia (original description), Port de Bône, Senegal and the Canary Islands. This species appears to be the closest in form to the original descriptions (as much as we have) of Cymadusa filosa . Unfortunately the original material appears to be lost and the only material in the Paris Museum was from Dakar, Senegal or from the Canary Islands. This material could not be used as neotype material because these specimens are not from the Mediterranean Sea and therefore not the type locality.

Cymadusa filosa is close morphologically to both Cymadusa setosa and Cymadusa tattersalli n. sp. as the margins of gnathopod 2 and antenna 2 are densely setose. However, it differs from C. tattersalli by not having a mid-palmar tooth on the palm of gnathopod 2 and by having an elongate carpus of gnathopod 1. Cymadusa filosa differs from the others in the ‘ filosa ’ group by having densely setose margins on gnathopod 2 and antenna 2, by having a long and acute anteroventral lobe on the merus of gnathopod 1; a long and narrow gnathopod 1 carpus and a rounded carpal lobe; no mid-palmar tooth on the palm of gnathopod 2 palm; a strongly setose uropod 3 mainly with robust setae.

Habitat. The material described does not have any habitat data attached.

Distribution. This species and its synonymies have quite a wide distribution ( Map 1 ). The type locality is in the Mediterranean Sea and the range extends to the Indian Ocean ( Madagascar) and the Pacific Ocean ( New Caledonia). This apparently disjunct distribution is hard to explain. There are a number of factors that may influence this distribution. Some of this distribution may be accounted for by introduction. One of the reasons for mentioning this is that Chevreux (1900), when describing Cymadusa hirsuta , commented that the specimens were collected from the bottom of pilot boats and around the schooner he was based on. This may indicate that one of the factors contributing to the wide distribution may be human dispersal. This has yet to be tested with cladistic analysis.

Figures

MAP 1. Global distribution of Cymadusa filosa Savigny, 1816 (*), Cymadusa ledoyeri n. sp. (•), Cymadusa tattersalli n. sp. (*), Cymadusa imbroglio Rabindranath, 1972 (Δ), Cymadusa setosa (Haswell, 1879) (v), Cymadusa vadosa Imbach, 1967 (&).