Lanceola Say, 1818

Zeidler, Wolfgang, 2009, A review of the hyperiidean amphipod superfamily Lanceoloidea Bowman & Gruner, 1973 (Crustacea: Amphipoda: Hyperiidea), Zootaxa 2000, pp. 1-117 : 10-11

Genus Lanceola Say, 1818

Lanceola Say, 1818: 317–318 . Bovallius 1885: 3–6; 1887b: 553; 1887c: 28. Stebbing 1888: 1301–1302. Sars 1900: 14–15. Woltereck 1909: 157–158. Schellenberg 1927: 593. Pirlot 1929: 42; 1938: 32–33. Bowman & Gruner 1973: 20. Vinogradov et al. 1982: 50. Shih & Chen 1995: 27. Vinogradov 1999: 1170.

Type species. Lanceola pelagica Say, 1818 based on two female specimens. Type material could not be found at the Academy of Natural Sciences of Philadelphia ( Zeidler 1997) and is presumed lost. This is not an ideal situation since the true identity of L. pelagica is uncertain. However, despite Say’s brief description, most authors agree with Bovallius’s (1885) evaluation that Say was referring to a species of the genus Lanceola , as is understood by modern taxonomists. It is considered a doubtful synonym of L. sayana Bovallius, 1885 . The type locality is the “Gulf Stream” (Atlantic), collected by Captain James Hamilton.

Diagnosis. Body length 8–45 mm. Cuticle often thin, translucent. Eyes small or inconspicuous, reniform or composed of paired crystalline cones. Antennae 1 with large, often curved, callynophore with three small terminal articles (fused in L. sayana ); terminal article varies in size and shape and can be diagnostic. Antennae 2 usually much longer than A1, rarely subequal in length ( L. clausi pirloti ). Maxillae 1; palp with feathered seta on outer distal corner, inner margin denticulate; inner lobe with broad distal margin. Maxillae 2; setae on lobes vary in number but inner always with more than outer. Gnathopods 1 & 2, pereopods 3 & 4 simple with dactylus inserted terminally. Pereopod 5 with retractile, hooded dactylus, or subchelate, rarely with nonretractile dactylus ( L. falsa ). Pereopods 6 & 7 with retractile, hooded dactyls or rarely with non-retractile dactyls ( L. falsa ).

Fourteen species.

Sexual dimorphism. Sexual dimorphism is not very marked in Lanceola . Females have a slightly more inflated pereon and the rostrum, if present, is sometimes more prominent than in males, especially for mature specimens. Juvenile females can often be distinguished by the oostegite buds at the base of gnathopod 2 and pereopods 3–5 in addition to the gills. Males generally reach maturity at a smaller size and in mature specimens the first antennae can be slightly more robust, especially the callynophore; also the telson can be relatively longer than in females. Males also have small genital papillae medially, near the base of the seventh pereopods.

Remarks. Lanceola is a relatively distinctive genus closely related to Scypholanceola . Species of Lanceola are very similar in gross morphology, making identification difficult in some instances. Apart from the morphology and relative lengths of appendages, other characters that can be useful for identification are the presence/absence and morphology of the rostrum and the morphology of the terminal article of the first antennae. In addition Lanceola can be divided into two groups based on eye morphology; those with eyes composed of paired crystalline cones, represented by species inhabiting surface waters ( L. felina , L. intermedia , L. sayana and L. galatheae sp. nov.) and those with reniform or barely discernable eyes, represented by species inhabiting mainly deeper waters (the remaining species).

Various authors have described twenty-nine species, subspecies or varieties of Lanceola . Some are considered synonyms while L. aestiva Stebbing, 1888 has been removed to Scypholanceola and L. stephenseni Chevreux, 1920 and L. remipes Barnard, 1932 have been removed to Megalanceola . The status of two species, L. pelagica Say, 1818 and L. murrayi Norman, 1900 is uncertain because they were inadequately described. Lanceola pelagica is a doubtful senior synonym of L. sayana Bovallius, 1885 , but because its identity is uncertain, and it is a name that has not been used for more than fifty years, it should be rejected for the sake of nomenclature stability. Lanceola murrayi is considered a doubtful synonym of L. felina Bovallius, 1885 .

The genus was first reviewed by Bovallius (1887c) who recognised L. pelagica and five species he described earlier ( Bovallius 1885). Additional taxa have been added by Stebbing (1888), Norman (1900), Woltereck (1909), Shoemaker (1945) and Vinogradov (1956, 1957, 1960a, 1962, 1964, & 1970). In the most recent and only review since Bovallius (1887c), Vinogradov et al. (1982) recognise twelve species and four subspecies. The current review is in general agreement with Vinogradov et al. (1982) with the addition of two species, described here, as new to science. Thus, Lanceola currently consists of fourteen species and four subspecies.