Krynickillus melanocephalus explained

Krynickillus melanocephalus is a species of air-breathing land slug, a terrestrial gastropod mollusc in the family Agriolimacidae. It is an invasive species, spreading from regions around the Black Sea to Northern and Central Europe.

Identification

The species resembles in form other agriolimacid slugs (notably Deroceras), so has the pneumostome in the rear half of the mantle and a tapering tail without a marked keel. However, it grows larger than Deroceras species (60 mm or occasionally more). The most distinctive feature is the deep black tentacles, head, and nape, with the dark colouration still visible under the front of the mantle. The congener Krynickillus urbanskii (Wiktor, 1971), occurring in Romania, Bulgaria and Turkey, has a paler black head and a pale nape.^[1]

Distribution

The natural range of Krynickillus melanocephalus is the Caucasus, Crimea, eastern Turkey and northern Iran.^[2] It has been introduced more widely within Europe: further parts of Ukraine (e.g. Kyiv),^[3] further parts of Russia (Moscow, Novgorod and Tverskaya oblasts),^[4] Germany (since 1994),^[5] Latvia (since 1997),^{[6] [7]} Belarus (since 2009),^[8] Sweden (since 2015),^[9] Lithuania (since 2017),^[10] Finland (since 2017),^[9] Hungary (since 2019),^[11] Slovakia (since 2020),^[12] Poland (since 2022),^[13] and Estonia.^[9]

Ecology

In its introduced range the species becomes adult in autumn and dies off in winter. It has spread from gardens to adjacent habitats, including woodland and meadows. Although it has sometimes been reported as a pest of crops, others have suggested that a diet of algae, fallen fruit, and fungi makes it less of a threat.^[9] In its native range this is a forest species.^[1] In experiments, slugs laid far more eggs in leaf litter than in moss, soil or gravel.^[14]

Notes and References

1. Wiktor . A. . Agriolimacidae (Gastropoda: Pulmonata) – a systematic monograph . Annales Zoologici . 2000 . 49 . 4 . 347–590 .
2. Лихарев И. М., Виктор А. Й. (1980). Слизни фауны СССР и сопредельных стран (Gastropoda terrestria nuda). Фауна СССР, Моллюски, том 3, вып. 5, Ленинград
3. Korol . E. . Korniushin . A.V. . Introduced population of Krynickillus melanocephalus (Mollusca, Gastropoda, Stylommatophora) recorded in Kyiv and preliminary results of its helminthological investigation . Vestnik Zoologii . 2015 . 36 . 6 . 57–59 . 10.13140/RG.2.1.5074.4809.
4. Шиков Е. В. (2013). Адвентивные виды наземной малакофауны городов Московской, Новгородской и Тверской областей. In: Сохранение степных и полупустынных экосистем Евразии: тезисы международной конференции, Алматы, 13-14 марта 2013 г. / Ред. С.Л. Скляренко, Н.П. Огарь, Т.Н. Дуйсебаева - Алматы: АСБК, 143.
5. Meng . S. . Bössneck . U. . Meng S., Krynickillus melanocephalus Kaleniczenko, 1851 in Deutschland eingeschleppt (Gastropoda: Stylommatophora: Agriolimacidae) . Malakologische Abhandlungen des Staatliches Museum für Tierkunde Dresden . 1999 . 19 . 303–309.
6. Stalažs . A. . Šteffek . J. . Dreijers . E. . Cepaea vindobonensis (C. Pfeiffer, 1828) in Latvia . Acta Universitatis Latviensis . 2008 . 745 . Biology . 199–203 .
7. Šteffek . Jozef . Stalažs . Arturs . Dreijers . Edgars . Snail fauna of the oldest cemeteries from Riga (Latvia) . Malacologica Bohemoslovaca . 29 September 2008 . 7 . 79–80 . 10.5817/MaB2008-7-79. free .
8. Ostrovsky . A.M. . Новые находки синантропных видов слизней Limacus flavus (Linnaeus 1758) и Krynickillus melanocephalus Kaleniczenko, 1851 (Mollusca, Gastropoda, Stylommatophora) в Беларуси [New records of synanthropic species of slugs ''Limacus flavus'' (Linnaeus 1758) and ''Krynickillus melanocephalus'' Kaleniczenko, 1851 (Mollusca, Gastropoda, Stylommatophora) in Belarus] . Ruthenica . 27 . 14 . 155–158 . 10.35885/ruthenica.2017.27(4).2. 2024-02-21 .
9. von Proschwitz . T. . Rapid invasion of the slug Krynickillus melanocephalus Kaleniczenko, 1851 in Sweden and some notes on the biology and anthropochorous spread of the species in Europe (Gastropoda: Eupulmonata: Agriolimacidae) . Folia Malacologica . 11 August 2020 . 28 . 3 . 227–234 . 10.12657/folmal.028.018. free .
10. Stalažs . A. . Dreijers . E. . Ivinskis . P. . Rimšaitė . J. . Džiugelis . M. . Records of Krynickillus melanocephalus Kaleniczenko, 1851 (Gastropoda: Agriolimacidae) in Lithuania . Bulletin of the Lithuanian Entomological Society . 2017 . 1 . 29 . 124–128.
11. Turóci . Á. . Fehér . Z. . Krízsik . V. . Páll-Gergely . B. . Two new alien slugs, Krynickillus melanocephalus Kaleniczenko, 1851 and Tandonia kusceri (H. Wagner, 1931), are already widespread in Hungary . Acta Zoologica Academiae Scientiarum Hungaricae . 7 August 2020 . 66 . 3 . 10.17109/AZH.66.3.265.2020. free .
12. Čejka . T. . Beran . L. . Coufal . R. . Dvořák . L. . Hlaváč . J.Č. . Horáčková . J. . Horsáková . V. . Juřičková . L. . Kosová. T. . Čačaný . J. . Szabóová . D. . 2021-09-16 . Malacological news from the Czech and Slovak Republics in 2020 . Malacologica Bohemoslovaca . 20 . 56–74 . 10.5817/MaB2021-20-56 . free.
13. Maćkiewicz . J.J. . Borys . O. . First record of invasive slug Krynickillus melanocephalus Kaleniczenko, 1851 (Gastropoda: Eupulmonata: Agriolimacidae) in Poland . Folia Malacologica . 2023 . 31 . 4 . 229–235 . 10.12657/folmal.031.024. free .
14. Watz . J. . von Proschwitz . T. . Egg-laying habitat selection of the invasive slug Krynickillus melanocephalus Kaleniczenko, 1851 (Gastropoda: Eupulmonata: Agriolimacidae) . Folia Malacologica . 2023 . 31 . 4 . 222–228 . 10.12657/folmal.031.029. free .