Thalamita poissonii

Thalamita poissonii (Audouin, 1826)

Portunus Poissonii Audouin, 1826:84 [Egypt].

Thalamita integra var. africana Miers, 1881a:218.

Thalamita africana.—Sourie, 1954b:151.—Monod, 1956:186, figs. 213–217.—Rossignol, 1957:124 [key].—Guinot and Ribeiro, 1962:46.—Crosnier, 1962:116 [discussion].—Ribeiro, 1964:5.—Forest and Guinot, 1966:61.—Uschakov, 1970:455 [listed].—Stephenson, 1972:19 [key], 44 [listed].

Thalamita integra africana.—Stephenson and Hudson, 1957:319 [key].

Thalamita poissonii.—Holthuis and Gottlieb, 1958:89, 118, pl. 2: fig. 10a,b [Eastern Mediterranean references].—Stephenson, 1976:23.

Thalmita africana.—Hartmann-Schröder and Hartmann, 1974:19 [erroneous spelling].

MATERIAL EXAMINED.—Pillsbury Material: None.

Other Material: Gulf of Guinea, no specific locality, 1956, Calypso, 1 (L).

Angola: Luanda (as St. Paul de Loanda), American Museum Congo Expedition 1909–1915, 23 Sep 1915, H. Lang, 3, 3 ov (W).

DESCRIPTION.—Rathbun, 1921:402.

Figures: Rathbun, 1921, fig. 5; Monod, 1956, figs. 213–217.

Male Pleopod: Monod, 1956, figs. 215–217 (Senegal).

Color: Little information is available on color in life of this species. Monod (1956) gave the following notes in his list of material: “rougeâtre” (p. 187); “doigts des chelipèdes (en alcool) rouges avec les apex noirs, la couleur se poursuivant, en liseré, le long des bords internes, dentigères” (p. 188).

MEASUREMENTS.—Our specimens have carapace widths of 28 to 41 mm; the carapace widths of ovigerous females are 28 to 31 mm.

DISTRIBUTION.—Eastern Atlantic and Indo-West Pacific. In eastern Atlantic, from eastern Mediterranean and off West Africa at scattered localities between the Canary Islands and Angola, in depths between the littoral zone and about 30 m; Indo-West Pacific from localities between Japan and Madagascar and the Red Sea (Crosnier, 1962). Monod (1956) summarized the West African literature and reported material from localities off Mauritania, Senegal, Guinea, and Angola. Records since then include the following.

Cape Verde Islands: Baía de Porto Grande, São Vicente, 4–6 and 8 m (Guinot and Ribeiro, 1962; Ribeiro, 1964).

Senegal: Baie de Dakar (Sourie, 1954b).

Guinea: No specific locality (Uschakov, 1970).

Principe: In front of [Cais de] Santana, 11 m (Forest and Guinot, 1966).

São Tomé: 00°25′15″N, 06°43′05″E, 8–30 m; Baía de Ana de Chaves, 5 m; in front of Ponta Diogo Nunes, 4 m; Morro Peixe, 0–4 m (all Forest and Guinot, 1966).

Gabon: 00°40′S, 08°46′25″E, 18 m (Forest and Guinot, 1966).

Angola: Baía de Luanda (Guinot and Ribeiro, 1962). Luanda (as St. Paul de Loanda) (Stephenson, 1976). Between Cacuaco and Lobito-Benguela (Hartmann-Schröder and Hartmann, 1974).

GERYONIDAE Colosi, 1923:249.

EASTERN ATLANTIC GENERA.—Due to the uncertainty of the taxonomic status of this family and of the genera sometimes assigned to it, we are unable to give here a reliable list of the eastern Atlantic geryonid genera. Guinot (1971:1077) included in the Geryonidae the following three genera that are represented in the eastern Atlantic: Geryon, Paragalene, and Progeryon; of these only Geryon is known from tropical West Africa.

Paragalene Kossmann (1878:253). Type-species: Paragalene neapolitana Kossmann, 1878, a junior subjective synonym of Eriphia longicrura Nardo, 1869, by monotypy; gender: feminine; name 341 on Official List.

Progeryon Bouvier (1922:71). Type-species: Progeryon paucidens Bouvier, 1922, by monotypy; gender: masculine.

We are not convinced that these two genera are correctly assigned to the Geryonidae, but as we have not had the opportunity to study this question in detail, we follow Guinot, at least for the time being. The genus Platychelonion (p. 155), placed by Guinot (1971:1078) with some doubt in the Geryonidae, in our opinion finds a better place in the Xanthidae.

EASTERN ATLANTIC SPECIES.—The above-mentioned three genera are represented in the eastern Atlantic area by 6 species; only two of these have been found in tropical West African waters. The other four are as follows:

Geryon tridens Krøyer, 1837. North Atlantic from N Norway and Iceland to the British Isles and the North Sea; records from the Bay of Biscay, the Mediterranean and Morocco need to be verified and at least partially pertain to G. longipes; 32–690 m, usually deeper than 100 m (Christiansen, 1969).

Geryon longipes A. Milne Edwards, 1881. Bay of Biscay, Morocco, Mediterranean; 600–1370 m (Zariquiey Alvarez, 1968).

Paragalene longicrura (Nardo, 1869). Mediterranean (Algeria, Malta, Naples, Adriatic and Aegean Seas) and Madeira; 20-ca. 120 m (Türkay, 1976b).

Progeryon paucidens Bouvier, 1922. Off Morocco, 2165 m (Bouvier, 1922).

Monod (1956:337) recognized a single West African species: Geryon quinquedens Smith, synonymizing G. affinis with it. In the present publication two tropical West African species are distinguished: G. affinis and G. maritae, new species; G. quinquedens is thought to be restricted to East American waters.

Only one species of Geryon, G. maritae, was taken by the Pillsbury in West African waters.

Geryon Krøyer, 1837:10, 20, 21 [type-species: Geryon tridens Krøyer, 1837, by original designation and monotypy; gender: masculine; name 309 on Official List].

Chalaepus Gerstaecker, 1856:118 [type-species: Cancer trispinosus Herbst; 1803, by monotypy; gender: masculine].

MATERIAL EXAMINED.—Pillsbury Material: None.

Other Material: Azores: E of Corvo, 39°41′35″N, 31°04′07″W of Paris (= 28°44′07″W of Greenwich), 844 m, sand and gravel, 7 Aug 1888, Princesse Alice Sta 222, syntypes, 1, 1 (MP).

SE of Madeira: 32°42′N, 16°43′W, 670 m, tent trap, 13 Mar 1976, Onversaagd Sta 63, 1, 1 ov (L).

Cape Verde Islands: 16°44′N, 24°48′05″W, 692 m, hard bottom, 21–22 Jul 1901, Princesse Alice Sta 1138, 1 (MP).

DESCRIPTION.—A. Milne Edwards and Bouvier, 1894:41–45; Christiansen, 1969:87.

Figures: A. Milne Edwards and Bouvier, 1894, figs. A, C, pl. 1 (color); Christiansen, 1969, fig. 35.

Male Pleopod: We have found no illustrations of the male pleopod of this species. Sankarankutty (1968:51) remarked that it was similar to that of G. maritae as figured by Doflein (1904).

Color: A colored figure of one of the type-specimens was published by A. Milne Edwards and Bouvier (1894, pl. 1). It shows a pale brown crab with the cervical groove and posterolateral margins, as well as the spine on the carpus, with a pink hue; the central part of the carapace is somewhat greenish. Kjennerud (1967:194) remarked of her specimen: “The colour of the specimen before it was preserved in alcohol was dull yellow with patches of red and red brown, the tips and the margins of the dactyls in the walking legs were dark brown. In general it may be said that the colour was very like the colour of one of the type-specimens illustrated by Milne-Edwards and Bouvier.” Christiansen (1969:85) on the other hand described the color as “red to brick-red.” A. Milne Edwards and Bouvier (1899:35) mentioned a probably abnormal specimen “à pattes blanches”

MEASUREMENTS.—The male and female syntypes examined have the carapace lengths 109 and 112 mm, the carapace widths 134 and 135 mm, respectively. In the male and female from Madeira the carapace widths are 140 and 145 mm, respectively. In the male from the Cape Verde Islands the carapace length is 133 mm, the carapace width 158 mm. A. Milne Edwards and Bouvier (1894) gave the following measurements of some of the types: males, carapace lengths 15, 97, and 133 mm, carapace widths 17, 112, and 153 mm, respectively; females, carapace length 128 mm, carapace width 14–(?) mm. (Due to a printer's error the last digit of this number was not printed so that the width may be anywhere between 140 and 149 mm). One of Saemundsson's (1937) specimens was 160 mm long by 180 mm wide; Kjennerud's (1967) male had a length of 150 mm and a width of 180 mm. The 5 males reported upon by Mason and Davidson (1969) had carapace widths ranging from 192 to 210 mm. In contrast to these large specimens are the specimens reported upon by Hansen (1908), the male of which was 40 mm long, the ovigerous female 42 mm. The only other ovigerous female of which the measurements are known is the one (cb 145 mm) from Madeira (above). A. Milne Edwards and Bouvier, (1894:43) mentioned the eggs as very small. Hansen (1908:19) gave the egg size in his specimen as 0.5–0.6 mm.