''Spurilla neapolitana'', the Neapolitan spurilla, is a
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
sea slug
Sea slug is a common name for some Marine biology, marine invertebrates with varying levels of resemblance to terrestrial Slug, slugs. Most creatures known as sea slugs are gastropods, i.e. they are Sea snail, sea snails (marine gastropod moll ...
, an aeolid nudibranch, a
marine gastropod
Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, freshwater, and fro ...
mollusk
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...
in the
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Aeolidiidae
Aeolidiidae, a family of aeolid nudibranchs, are a family of sea slugs, shell-less marine gastropod mollusc
Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around ...
. It is native to the western Atlantic Ocean, the Caribbean Sea and the Mediterranean Sea. This species was
first described as ''Eolis neapolitana'' by the Italian naturalist
Stefano delle Chiaje
Stefano Delle Chiaje (25 April 1794 – 18 December 1860) was an Italian zoologist, botanist, anatomist and physician.
Delle Chiaje studied medicine in Naples, where he was a pupil of Giuseppe Saverio Poli. Together they started compiling books ...
in 1841. However, although some authorities quote the year as 1823, the species does not appear in the first volume of delle Chiaje's memoirs, which was published that year.
The species was later reassigned to the
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''
Spurilla
''Spurilla'' is a genus of sea slugs, aeolid nudibranchs, marine gastropod molluscs in the family Aeolidiidae.Gofas, S.; Rosenberg, G. (2013)''Spurilla'' Bergh, 1864.In: MolluscaBase (2016). Accessed through: World Register of Marine Species on ...
''.
Distribution
''Spurilla neapolitana'' is found in shallow temperate waters in the Mediterranean Sea, the western Atlantic Ocean, the Caribbean Sea, the Gulf of Mexico and Baja California.
[ Molecular studies have shown that this is a ]species complex
In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
consisting of at least three species. The type ''Spurilla neapolitana'' is found in the eastern Atlantic Ocean, from Cape Verde and the Azores to Portugal, and in the Mediterranean Sea. The western Atlantic population was denoted as ''Spurilla braziliana'' by MacFarland (1909) and the Pacific specimens may also be ''S. braziliana''.
Description
''Spurilla neapolitana'' is a large nudibranch, growing to a length of in the Mediterranean Sea. The rhinophore
A rhinophore is one of a pair of Chemoreceptor, chemosensory club-shaped, rod-shaped or ear-like structures which are the most prominent part of the external head anatomy in sea slugs, Marine (ocean), marine gastropod opisthobranch mollusks suc ...
s (the pair of sensory structures on the dorsal surface of the head) are lamellate. The cerata
:''The tortrix moth genus ''Cerata'' is considered a junior synonym of ''Cydia (genus), Cydia.
Cerata, singular ceras, are anatomical structures found externally in nudibranch sea slugs, especially in aeolid nudibranchs, marine animal, marine opi ...
(outgrowths of the body) are also flattened and have opaque white tips. These tips are known as cnidosac
A cnidosac is an anatomical feature that is found in the group of sea slugs known as aeolid nudibranchs, a clade of marine (ocean), marine opisthobranch gastropod mollusk, molluscs. A cnidosac contains cnidocytes, stinging cells that are also known ...
s and are defensive structures armed with cnidocyte
A cnidocyte (also known as a cnidoblast) is a type of cell containing a large secretory organelle called a ''cnidocyst'', that can deliver a sting to other organisms as a way to capture prey and defend against predators. A cnidocyte explosively ...
s (stinging cells) garnered from sea anemone
Sea anemones ( ) are a group of predation, predatory marine invertebrates constituting the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemone ...
s that the nudibranch has eaten.[ The general colour of this species is orange or pinkish, perhaps depending on what it has been eating, often with dark streaking where the tortuous ]digestive gland
The hepatopancreas, digestive gland or midgut gland is an organ of the digestive tract of arthropods and molluscs. It provides the functions which in mammals are provided separately by the liver and pancreas, including the production of digestive ...
is visible through the translucent skin and the walls of the cerata. Some individuals have opaque patches of white on the body wall.
Habitat
Minimum recorded depth is 0 m.[Welch J. J. (2010). "The “Island Rule” and Deep-Sea Gastropods: Re-Examining the Evidence". '' PLoS ONE'' 5(1): e8776. doi:10.1371/journal.pone.0008776.]
Feeding habits
''Spurilla neapolitana'' feeds on sea anemones. The cnidocytes pass unharmed through the gut of the nudibranch to the tip of the cerata where they are stored, to be used in the animal's defence. The nudibranch's tissues harbour live intracellular zooxanthellae
Zooxanthellae (; zooxanthella) is a colloquial term for single-celled photosynthetic organisms that are able to live in symbiosis with diverse marine invertebrates including corals, jellyfish, demosponges, and nudibranchs. Most known zooxanthell ...
(photosynthetic single celled organisms), also derived from the sea anemone. It has been shown that the nudibranch's faeces
Feces (also known as faeces American and British English spelling differences#ae and oe, or fæces; : faex) are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the ...
contain live zooxanthellae, theoretically capable of reinfecting sea anemones, and this may be an important means by which the sea anemones acquire their zooxanthellae.
References
Further reading
*
{{Taxonbar, from=Q5049635
Aeolidiidae
Gastropods described in 1841
Taxa named by Stefano delle Chiaje