Mimonectes steenstrupi Bovallius, 1885: 12 –15, pl. II, figs 13, 14. Bovallius 1887 a: 15; 1887 b: 558–559, pl. 47, figs 111–115; 1889: 70–73, pl. 6, figs 11–21. Woltereck 1904 a: 622 (key); 1904 b: 629 (key). Stephensen 1923: 7 (part). Schellenberg 1927: 600, fig. 11.
Micromimonectes steenstrupi Stephensen & Pirlot 1931: 534 –538, figs 13, 14. Stephensen 1932: 375 (list); 1933: 64–66, figs 29–30.
Archaeoscina steenstrupi Pirlot 1939: 18 –19. Vinogradov 1956: 200 –201, 213 (map), figs 2, 3; 1962: 2. Hurley 1969: 33. Vinogradov 1970: 384 (table). Vinogradov et al. 1982: 44 –46, fig. 3. De Broyer & Jazdzewski 1993: 106. Vinogradov 1999: 1169, fig. 4.34. Vinogradov et al. 2004: 9, 25 (table).
Archaeoscina bonnieri Stebbing, 1904: 19 –20, pl. 3 A.
Micromimonectes irene Woltereck, 1906: 190 –191, figs 1–4; 1909: 154, pl. 5, fig. 12. Barnard 1932: 250 –251, fig. 157.
Micromimonectes typus physosoma Woltereck, 1906: 191 –194, figs 5, 6.
Type material
Type material of Mimonectes steenstrupi could not be found at the SMNH or in Uppsala. However, the ZMUC has one syntype female (CRU 8250) labeled “ Micromimonectes steenstrupi Bov. det. 57 ° 45 ”N, 43 ° 53 ”W, W. Olrik ded. 1861 ”. The locality is southeast off Greenland, just east of Davis Strait, which corresponds to the type locality “North Atlantic. The mouth of Davis Strait”. It is specimen 2 of Stephensen and Pirlot (1931) and is illustrated here (Fig. 1) and used in the diagnosis of the species.
Type material of synonyms
The unique type of A. bonnieri is in the BMNH (1905.3.8.21). The specimen, a juvenile male less than 2.0 mm long, has been dissected and mounted on one microscope slide. An examination of these remains, although in poor condition, has confirmed the synonymy, when compared with other male specimens.
Type material of Micromimonectes irene and M. typus physosoma could not be found in any major European museum and is considered lost. Both species are based on female specimens, the former ovigerous, and judging by Wolterecks (1906) description and figures, are indistinguishable from females of A. steenstrupi.
Material examined (17 females, 6 males)
Types. Syntype of Mimonectes steenstrupi (ZMUC CRU 8250) from the North Atlantic, just east of Davis Strait [57 ° 45 ”N, 43 ° 53 ”W], collected by W. Olrik, 1861. The unique type of Archaeoscina bonnieri (BMNH 1905.3.8.21) from the eastern North Atlantic, Bay of Biscay, 400 – 300 fathoms: one microscope slide of dissected appendages.
Other material examined. North Atlantic: Female (ZMUC CRU 4348); S. of Iceland [60 ° 18 ”N, 16 ° 48 ”W]; collected by Ryder, 28 May 1882. Female (ZMUC CRU 4349); Davis Strait [64 ° 46 ”N, 53 ° 35 ”W]; collected by Moberg. Two females (ZMUC CRU 4350]; S. of Davis Strait [56 ° 56 ”N, 51 ° 17 ”W]; collected by Godthaab (Stn. 10), 3000 mw, 3 June 1928. Four females (ZMUC CRU 4351); Davis Strait [62 ° 19 ”N, 56 °00”W]; collected by Godthaab (Stn. 24), 2500 mw, 14 June 1928. Juvenile female (ZMUC CRU 4358); off Sierra Leone [8 ° 26 ”N, 15 ° 11 ”W]; collected by Dana (Stn. 4003 V), 2000 mw, 9 March 1930. South Atlantic: Female (ZMUC CRU 4355); near Gulf of Guinea [7 ° 34 ”S, 8 ° 48 ”W]; collected by Dana (Stn. 3998 IX), 3000 mw, 1 March 1930. Two juvenile females (ZMUC CRU 4356 & 4357); near Gulf of Guinea [0° 31 ”S, 11 °02”W]; collected by Dana (Stns. 4000 VII & X), 5000 & 2000 mw, 4 March 1930. South Indian: Female (ZMUC CRU 4352); N. of CocosKeeling Is. [6 °01”S, 93 ° 12 ”E]; collected by Dana (Stn. 385 III), 200 mw, 14 Oct. 1929. South Pacific: Three females (ZMUC CRU 4353 & 4354); E. of New Zealand [46 ° 43 ”S, 176 °08.5”E]; collected by Dana (Stns. 3642 II & III), 2500 & 2000 mw, 9 Jan. 1929. NorthEast Pacific: Male (SAMA C 6093); [49 ° 58 ”N, 144 ° 56.2 ”W]; ex M. Galbraith; 1200 m, 8 July 1998. Two juvenile males (SAMA C 6094); off Queen Charlotte I. [53 ° 59.91 ”N, 138 ° 44.99 ”W]; ex. M. Galbraith; 1500 – 1000 m, 26 Sept. 2001. Two males (SAMA C 6095); off Queen Charlotte I. [51 ° 59.99 ”N, 135 ° 20.05 ”W]; ex. M. Galbraith; 1500 – 1000 m, 30 Sept. 2001.
Diagnosis
Body length of females up to 10.0 mm with pereon diameter of about 9.0 mm; males up to 3.5 mm. Pleon length in males about 0.6 x pereon. Antennae 1 as long as head and first 2.5 pereonites in males; callynophore as long as peduncle in females, twice length peduncle in males; terminal article about twice length preceding one, rounded, slightly bulbous. Antennae 2 about halflength A 1; the two terminal articles as wide as long. Mandibular palp; length third article about 1.7 x first two articles combined. Pereopods 3–6 similar in length; in males P 5 marginally longer. Pereopod 7 marginally shorter than P 6. Merus length of P 3 & 4 about 0.6 x carpus; of P 5 & 6 about 0.66 x (female) or 0.75 x (male) carpus; of P 7 about 0.5 x carpus. Carpus length of P 3–7; slightly more than propodus in females, subequal in length to propodus in males; dactylus sharp, relatively long, about 0.5 x length propodus for P 3–6; for P 7 about 0.6 x length propodus in females, slightly longer in males. Uropod 3; peduncle width about 0.3 x length in females, 0.4 x length in males. Telson length about 0.3 x peduncle of U 3 in females, 0.4 x in males.
Remarks
Prior to this review this was the only valid species of Archaeoscina, with A. stebbingi considered a doubtful synonym. According to Woltereck (1909) A. stebbingi differs from A. steenstrupi mainly in the broader carpus of the gnathopods and that the third article of the mandibular palp is at least three times longer than the first two combined, although he illustrates it as only one and half times as long. Also, according to his illustration, pereopod 5 is relatively long, about twice the length of pereopod 7. Even accounting for some inaccuracy in the illustration, this last character distinguishes A. stebbingi from A. steenstrupi and in the absence of type material it must be considered a valid species.
Archaeoscina steenstrupi differs from the new species described here in a number of characters, as detailed under that species. Superficially, females of the new species are readily recognized by the relatively larger pereopods and urosome when compared with specimens of A. steenstrupi of similar size (compare figs 1 & 4 drawn to the same scale).
Incidentally, Vinogradov et al. (1982) are of the opinion that the type of A. bonnieri is a juvenile female. However, the morphology of the antennae, as illustrated by Stebbing (1904), indicates that the specimen is a male which is confirmed by my examination of the remains of the specimen.
Nothing is known of the biology of this species apart from distribution and catch records.
Distribution
Archaeoscina steenstrupi is a relatively uncommon but widely distributed species having been found in all the worlds oceans. In the Atlantic it has been recorded from 65 °N to 43 °S, in the northwest Pacific to 60 °N and in the northeast Pacific from 54 °N to 27 °S. In the Indian Ocean it has only been found in the tropical waters near Sumatra. Vinogradov (1962) also recorded it from Antarctic waters (63 °03S, 161 ° 59 E). In the northwestern Pacific Vinogradov (1956) found it in catches from depths of 200–500 m, 300–500 m, and also in all catches from depths of 700 m, 1000 m and more to the surface.