Elisesione, Salazar-Vallejo, Sergio I., 2016

Salazar-Vallejo, Sergio I., 2016, Elisesione, a new name for Wesenbergia Hartman, 1955, and the description of a new species (Annelida, Hesionidae), ZooKeys 632, pp. 1-12 : 3-5

Taxon classification Animalia Phyllodocida Hesionidae

Elisesione nomen novum

Hesionella Wesenberg-Lund, 1950: 14.

Wesenbergia Hartman, 1955: 41; Fauchald 1977: 77; Pleijel 1998: 112, 163 (non Kryger 1943).

Type species.

Hesionella problematica Wesenberg-Lund, 1950, by monotypy.

Etymology.

The name is a combination of the first name of the late Elise Wesenberg-Lund, and Hesione , which is the type genus for the family, but in order to make it more euphonic, the first two letters of the genus-group name are suppressed; the new name emphasizes the similarities between these two genera. Gender feminine.

Diagnosis

(emended). Hesionini with two antennae; palps simple, lateral to antennae. Eight pairs of tentacular cirri. Dorsal cirri with short or long cirrophores. Notochaetae absent. Aciculae colorless or blackish. Acicular lobes single or double. Neurochaetae with blades bidentate, guards approaching subdistal tooth, or absent. Prepygidial segment with dorsal cirri about 10 times longer than ventral cirri.

Remarks.

Wesenbergia Kryger, 1943 was proposed for a group of chalcid hymenopterans, but the name was overlooked by Hartman (1955) when she proposed the same genus-group name for hesionid polychaetes. Despite Wesenbergia Kryger, 1943 being considered a synonym of Macromesus Walker, 1848 within Hymenoptera , the name still cannot be made available ( ICZN 1999, Art. 23, Principle of Priority).

Homonymies are not allowed in Zoological Nomenclature ( ICZN 1999, Chap. 12) and junior homonyms must be replaced (Art. 60). Further, the Code of Ethics includes ( ICZN 1999, Point 3) a recommendation for the procedure, especially if the author(s) involved are alive. There are no junior synonyms available and this explains why a new name must be proposed, and both authors involved are deceased.

As indicated above, Wesenbergia Hartman, 1955 is a junior homonym and must be replaced, even though the senior homonym is regarded as a junior synonym ( Heqvist 1960). In naming Wesenbergia , Hartman used the first word in the compound last name of Elise Wesenberg-Lund. Using this same principle, the new name, Elisesione , is derived from the first name of the author.

Elisesione nom. n. is closely related to Hesione as shown by Ruta et al. (2007). They differ, however, not only by the presence of simple palps in the former, but because the body is more or less cylindrical, not widened medially or posteriorly as in Hesione species. In fact, the lateral cushions, which are typically divided into 2-3 sections and can vary on their degree of lateral expansion in Hesione , are rather solid, undivided and projected anteriorly in Elisesione nom. n. This feature was noted in the original description when the body was characterized as scolopendriform ( Wesenberg-Lund 1950: 14). Further, the anterior eyes of Wesenbergia (only recorded for the shallow water species), are half-moon shaped and about three times larger than posterior ones; this is another feature not recorded for any Hesione species.

Savigny (1822: 39) included four anterior appendages in the generic diagnosis of Hesione , but because they were not included in the description ( Savigny 1822: 40), nor in the corresponding illustration (his plate 3, figure 3), they were regarded as a mistake. Grube (1867: 65) corrected this and later Chamberlin (1919: 185) used this in his key to genera. However, by regarding Hesione as having four antennae and eight pairs of tentacular cirri, de Quatrefages (1866) proposed Fallacia for species having two antennae: Hesione pantherina Risso, 1826 and Hesione proctochona Schmarda, 1861, whereas Claparède (1868: 541) proposed Telamone for species having two antennae and six pairs of tentacular cirri with Hesione sicula delle Chiaje, 1822 as its only species. Fallacia and Telamone are junior synonyms of Hesione ( Fauvel 1911: 374, Chamberlin 1919: 186, Pleijel 1998: 107), and Hesione sicula and Hesione pantherina have been regarded as synonyms ( Fauvel 1923: 233).

Distribution.

The two known species in the genus have been found in different ecological conditions and geographical regions. The type species, Elisesione problematica , was found in the North Atlantic, off Iceland, in sediments taken at 550 m depth, and the new species, Elisesione mezianei sp. n., was collected in the Western South Pacific, in hard substrates in shallow water (35 m), in the Wallis and Futuna Islands. Another species, previously recorded as Elisesione problematica from Japan ( Imajima 2003) differs from the nominal form in several features. For example, in the Japanese specimens palps are half as long as antennae (rather than about equal-sized), and ventral cirri extend beyond chaetal lobe (rather than short of it); pigmentation also differs because the Japanese specimens are brownish with dorsal cirrostyles banded, whereas the Icelandic specimens are pale yellowish.

Key to species of Elisesione nomen novum