Milax nigricans

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Milax nigricans
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Order: Stylommatophora
Family: Milacidae
Genus: Milax
Species:
M. nigricans
Binomial name
Milax nigricans
Distribution in Europe (missing Hungarian and N. French records)

Milax nigricans is a Mediterranean species of terrestrial slug in the family Milacidae.

Description[edit]

Extended length is up to 75 mm. As in other species of the family Milacidae, a prominent raised keel runs along the midline of the body from the back of the mantle to the tip of the tail. Milax nigricans is not distinguishable from Milax gagates on the basis of external characters: Milax nigricans is often black but can be a much paler grey even within the same population, and M. gagates can also be black.[4][5][6]

The most reliable anatomical character is the stimulator in the atrium of the distal genitalia. In M. nigricans, numerous large papillae protrude from one side of the stimulator, whereas in M. gagates, if there are any such papillae at all, they are few, small, and restricted to the distal half of the stimulator. Other internal characters are less reliable.[5][6]

Suggestions that M. nigricans and M. gagates are conspecific (e.g. [4]) have subsequently been refuted by studies of DNA.[6]

Living individual (A), preserved specimen (B), reproductive anatomy (C), atrium stimulator (D) with some of the papillae marked with red arrows. Abbreviations: a = atrium, ag = atrium glandula, at = atrium tubuli, bc = bursa copulatrix, dh = ductus hermaphroditicus, epi = epiphallus, ga = glandula albuminalis, gh = glandula hermaphroditica, ovi = oviductus, p = penis, pr = penis retractor, so = sperm-oviductus, sti = (atrial) stimulator, vd = vas deferens. Photography: Ágnes Turóci.[6]

Distribution[edit]

Milax nigricans is often abundant around the Mediterranean, especially in disturbed habitats: North Africa, Malta, Sicily, mainland Italy, Croatia, Sardinia, Corsica, southern France, Balearic Islands, northern and eastern mainland Spain, Canary Islands. In addition, local populations have been introduced further north in Europe and may persist: southern England (one record only), Munich, northern France, the Netherlands, Hungary.[5][6]

References[edit]

  1. ^ Kappes, H. (2017). "Milax nigricans (Europe assessment)". IUCN Red List of Threatened Species. 2017: e.T171115A85577928. Retrieved 27 May 2024.
  2. ^ Philippi, R.A. (1836). Enumeratio molluscorum Siciliae cum viventium tum in tellure tertiaria fossilium quae in itinere suo observavit. Vol. 1. Berlin: Sumptibus Simonis Schroppii et Sociorum. pp. 125, Tav. 8.
  3. ^ MolluscaBase eds. (ed.). "(2024). MolluscaBase. Milax nigricans (R. A. Philippi, 1836)". MolluscaBase. Flanders Marine Institute. Retrieved 26 May 2024.
  4. ^ a b Welter-Schultes, F.W. (2012). European non-marine molluscs, a guide for species identification. Göttingen: Planet Poster Editions. ISBN 9783933922755.
  5. ^ a b c Hutchinson, J.M.C.; Reise, H. (2013). "A persisting population of an introduced slug, Milax nigricans, in Dunkirk, France" (PDF). Mitteilungen der Deutschen Malakozoologischen Gesellschaft. 89: 35–38.
  6. ^ a b c d e Turóci, Á.; Hutchinson, J.M.C.; Schlitt, B.; Reise, H.; Rapala, M.; Páll-Gergely, B. (2023). "Five new introduced terrestrial slugs in Hungary". BioInvasions Records. 12: 711–729. doi:10.3391/bir.2023.12.3.08.