Short Communication
Short Communication
Elthusa nierstraszi nom. n., the replacement name for Elthusa parva (Nierstrasz, 1915), a junior secondary homonym of Elthusa parva (Richardson, 1910) (Isopoda, Cymothoidae)
expand article infoKerry A. Hadfield, Niel L. Bruce§, Nico J. Smit
‡ North West University, Potchefstroom, South Africa
§ Museum of Tropical Queensland, Townsville, Queensland, Australia
Open Access


The recent transfer of Elthusa parva (Richardson, 1910) from Ceratothoa created a homonymy with Elthusa parva (Nierstrasz, 1915). Elthusa parva (Richardson, 1910) has priority and Elthusa nierstraszi nom. n. is proposed as the new replacement name for the junior secondary homonym Elthusa parva (Nierstrasz, 1915).


Meinertia parva , Livoneca parva , junior homonym, new combination, marine fish parasite


Hadfield et al. (2016) in redescribing poorly characterised species of Ceratothoa Dana, 1852 transferred the species Ceratothoa parva (Richardson, 1910) to Elthusa Schioedte & Meinert, 1884. In so doing Elthusa parva (Nierstrasz, 1915) was rendered a junior secondary homonym.

According to Articles 23.3.5, 52 and 60.3 of the International Code of Zoological Nomenclature (Anon 1999) Elthusa parva (Richardson, 1910) (originally in combination with Meinertia Stebbing, 1893) has priority and a new name Elthusa nierstraszi nom. n. is proposed for Elthusa parva (Nierstrasz, 1915) to remove the homonymy.

Abbreviations.RMNH – Rijksmuseum voor Natuurlijke Historie (Naturalis Biodiversity Center).

Taxonomic history

Meinertia parva Richardson, 1910: 21, fig. 20.

Codonophilus parvus: Nierstrasz 1931: 132.

Ceratothoa parva: Trilles 1994: 127.

Elthusa parva: Hadfield et al. 2016: 75, fig. 12.

Livoneca parva Nierstrasz, 1915: 98, pl. IV, figs. 18, 19; 1931: 143.

Elthusa parva: Bruce 1990: 287.

Lironeca parva: Trilles 1994: 182.

Suborder Cymothoida Wägele, 1989

Superfamily Cymothooidea Leach, 1814

Family Cymothoidae Leach, 1814

Genus Elthusa Schioedte & Meinert, 1884

Elthusa nierstraszi nom. n.

Livoneca parva Nierstrasz, 1915: 98–99, pl. IV, figs. 18, 19; 1931: 143.

Elthusa parva : Bruce 1990: 287; Sidabalok 2013: 56.

Lironeca parva : Trilles 1994: 182.


Single ovigerous female (11 mm long; 5 mm wide), Kisser, Indonesia, coll. K. Schädler, 1898 (RMNH.CRUS.I.71).


Kisser (= Kisar?) Island, Moluccas, Indonesia (Nierstrasz 1915).




The new name honours the original author Hugo Frederik Nierstrasz (1872–1937).


Elthusa nierstraszi nom. n. replaces the name Elthusa parva (Nierstrasz, 1915), originally Livoneca parva Nierstrasz, 1915. Elthusa nierstraszi nom. n. has mesially directed, narrow anterolateral margins on pereonite 1; pereonite 7 not overlapping pleonite 1; pleonites all subequal in width and narrower than the pereon; and the posterior margin of the pleotelson forms a caudomedial point.

The cover date for Trilles’ (1994)Prodromus’ was 1991, but the work was most likely completed prior to that of Bruce (1990) and Trilles was simply retaining Livoneca parva in its original combination (albeit using the alternative incorrect spelling Lironeca; see Anon 1996). Prior to Bruce (1990) the name Livoneca (also as Lironeca) was largely used in the sense of Elthusa, and there is no possibility that Nierstrasz’s species would remain in or be returned to Livoneca, a strictly New World genus.


The financial assistance of the Claude Leon Foundation towards this research is acknowledged for KA Hadfield. The financial assistance of the National Research Foundation (NRF) towards this research is hereby acknowledged (NRF project IFR2011040100022, NJ Smit, PI). Opinions expressed and conclusions arrived at, are those of the authors and are not necessarily to be attributed to the NRF. Thanks to Karen van Dorp from Naturalis Biodiversity Center for her helpful assistance with the type material. We thank Julia Koburg (Townsville) for assistance in translating the German texts.


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