Stiliger is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of small and minute sacoglossan or sap-sucking sea slug

Slug

Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...

s. They are marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 gastropod mollusks in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Limapontiidae.

They somewhat resemble nudibranch

Nudibranch

A nudibranch is a member of what is now a taxonomic clade, and what was previously a suborder, of soft-bodied, marine gastropod mollusks which shed their shell after their larval stage. They are noted for their often extraordinary colors and striking forms...

s, but are not closely related to them. They are a rich green in color, caused by the green algae they eat.

Species

Species in the genus Stiliger include:

• Stiliger akkeshiensis Baba, 1935
• Stiliger auarita Caballer, Ortea & Moro, 2009
• Stiliger aureomarginatus Jensen, 1993
• Stiliger berghi Baba, 1937
• Stiliger costai Pruvot-fol, 1951
• Stiliger felinus
  Stiliger felinus
  Stiliger felinus, now known as Ercolania felina, is a minute black species of sacoglossan or sap-sucking sea slug. It is a marine gastropod mollusk in the family Limapontiidae.- Further reading :...
  
   (Hutton, 1882)
• Stiliger fuscovittatus Lance, 1962 - brown-streak stiliger
• Stiliger llerae Ortea, 1981
• Stiliger ornatus Ehrenberg, 1831
• Stiliger pusillus Baba, 1959
• Stiliger smaragdinus Baba, 1949
• Stiliger talis Ev. Marcus & Er. Marcus, 1956
• Stiliger vanellus 
• Stiliger viridis (Kelaart, 1858)
• Stiliger vossi Ev. Marcus and Er. Marcus, 1960

Species brought into synonymy :

• Stiliger bellulus (Orgibny, 1837) : synonym of Calliopaea bellula d'Orbigny, 1837
• Stiliger fuscatus Gould, 1870 : synonym of Ercolania fuscata (Gould, 1870)
• Stiliger lilianae Ev. Marcus & Er. Marcus, 1969 : synonym of Costasiella lilianae (Ev. Marcus & Er. Marcus, 1969)
• Stiliger llerai Ortea, 1981 : synonym of Stiliger llerae Ortea, 1981
• Stiliger mariae (Meyer & Möbius, 1865) : synonym of Calliopaea bellula d'Orbigny, 1837
• Stiliger modestus Lovén, 1844 : synonym of Alderia modesta (Lovén, 1844)
• Stiliger niger Lemche, 1935 : synonym of Ercolania nigra (Lemche, 1935)
• Stiliger noto Baba, 1959 : synonym of Hermaea noto
  Hermaea noto
  Hermaea noto is a species of sacoglossan sea slug, a shell-less marine opisthobranch gastropod mollusk in the family Hermaeidae....
  
   (Baba, 1959)
• Stiliger oophaga (Lemche, 1972) : synonym of Calliopaea oophaga Lemche in Gascoigne & Sartory, 1974
• Stiliger vesiculosus (Deshayes, 1853) : synonym of Calliopaea bellula d'Orbigny, 1837
• Stiliger zosterae Baba, 1959 : synonym of Hermaea zosterae
  Hermaea zosterae
  Hermaea zosterae is a species of sacoglossan sea slug, a shell-less marine opisthobranch gastropod mollusk in the family Hermaeidae....
  
  (Baba, 1959)