''Pseudunela marteli'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

sea slug Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are gastropods, i.e. they are sea snails (marine gastropod mollusks) that over evolutionary t ...

, an

acochlidian Acochlidiacea, common name acochlidians, are a taxonomic clade of very unusual sea snails and sea and freshwater slugs, aquatic gastropod mollusks within the large clade Heterobranchia. Acochlidia is a variant spelling. Description These ar ...

, a shell-less

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the family

Pseudunelidae ''Pseudunela'' is a genus of minute sea slugs, acochlidians, shell-less marine or temporary brackish or brackish gastropod mollusks in the clade Acochlidiacea. ''Pseudunela'' is the only genus in the family Pseudunelidae. ''Pseudunela'' is the t ...

. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

''marteli'' is in honour of author's "big-hearted friend and colleague" biologist Martin “Martl” Heß from

Ludwig Maximilian University of Munich The Ludwig Maximilian University of Munich (simply University of Munich or LMU; german: Ludwig-Maximilians-Universität München) is a public research university in Munich, Germany. It is Germany's sixth-oldest university in continuous operatio ...

, because the species has a large heart-bulb.

Distribution

''Pseudunela marteli'' is known from

Guadalcanal Guadalcanal (; indigenous name: ''Isatabu'') is the principal island in Guadalcanal Province of Solomon Islands, located in the south-western Pacific, northeast of Australia. It is the largest island in the Solomon Islands by area, and the seco ...

Solomon Islands Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its capita ...

and

Oyster Island Ellis Island is a federal government of the United States, federally owned island in New York Harbor, situated within the U.S. states of New York (state), New York and New Jersey, that was the busiest immigrant inspection and processing stati ...

Vanuatu Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of no ...

. The type locality is beach of “Art Gallery”,

Honiara Honiara () is the capital and largest city of Solomon Islands, situated on the northwestern coast of Guadalcanal. , it had a population of 92,344 people. The city is served by Honiara International Airport and the seaport of Point Cruz, and lie ...

, Guadalcanal, Solomon Islands.

Description

External morphology and anatomy of ''Pseudunela marteli'' is the same as in ''

Pseudunela viatoris ''Pseudunela viatoris'' is a species of sea slug, an acochlidian, a shell-less marine gastropod mollusk in the family Pseudunelidae. The specific name ''viatoris'' is after the Latin word “viator” (engl. pilgrim/voyager) according to its sup ...

'' with the following exceptions: Colour of

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 e ...

is greenish or orange-brownish. Eyes (30–35 µm) are pigmented and well visible externally. Foot length is up to half of the visceral hump. Subepidermal

spicule Spicules are any of various small needle-like anatomical structures occurring in organisms Spicule may also refer to: *Spicule (sponge), small skeletal elements of sea sponges *Spicule (nematode), reproductive structures found in male nematodes ( ...

s are more abundant in cephalic tentacles, foot and visceral hump.

digestive system The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller compone ...

: the

radula The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

formula is 57–59×1.1.?; rhachidian tooth with 3–4 denticles per side.

reproductive system The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pheromones are als ...

: the hollow curved penial stylet measures 130 µm in length, the stylet of basal finger is 30 µm long. The ampulla is sac-like; allosperm receptacles are absent in the examined specimen. The albumen and mucus glands are tubular; the membrane gland is sac-like.

Ecology

''Pseudunela marteli'' is a minute species that lives in the spaces between sand grains in saltwater habitats, and it is thus considered to be a mesopsammic, marine interstitial animal that is part of the

meiofauna Meiobenthos, also called meiofauna, are small benthic invertebrates that live in both marine and fresh water environments. The term ''meiofauna'' loosely defines a group of organisms by their size, larger than microfauna but smaller than macrofau ...

of marine sands.

References

This article incorporates CC-BY-2.5 text from the reference

External links

* {{Taxonbar, from=Q7255739 Pseudunelidae Gastropods described in 2011