''Sphaerosyllis bardukaciculata'' is a species belonging to the phylum

Annelida The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to variou ...

, a group known as the segmented worms.San Martín, G. (2005). Exogoninae (Polychaeta: Syllidae) from Australia with the description of a new genus and twenty-two new species. Records of the Australian Museum. 57(1): 39–152, available online at https://dx.doi.org/10.3853/j.0067-1975.57.2005.1438, pages 55–57, figs. 11A–G, 12A–E. ''Sphaerosyllis bardukaciculata'' is similar to ''Sphaerosyllis aciculata'' from Florida; its chaetae are almost identical; the former, however, differs by having longer antennae and anal cirri, as well as parapodial glands with granular material. The animal's name is derived from the Aboriginal word ''barduk'', meaning "near", alluding to the aforementioned likeness with ''S. aciculata''.

Description

The species' body is small, with a total length of and width of , including 24 chaetigers. It possesses short papillae on its dorsum. Its

prostomium The prostomium (From Ancient Greek, meaning "before the mouth"; : prostomia; sometimes also called the "acron") is the Cephalization, cephalized first body segment in an annelid worm's body at the anterior end. It is in front of (but does not in ...

is ovate, covered dorsally in part by the peristomium, showing 4 large eyes in a trapezoidal arrangement. Its antennae are longer than the prostomium, shorter than the combined length of its prostomium and palps. The

palp Pedipalps (commonly shortened to palps or palpi) are the secondary pair of forward appendages among chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to the chelicera ...

s are fused along their length, eliciting a dorsal furrow. Its dorsal cirri are short on its anterior segments, while a bit longer on its midbody and posterior segments; cirri are absent on chaetiger 2. Its parapodial glands are small, present from chaetigers 4-5. It shows anterior parapodia with 3-4 compound chaetae, with short and unidentate blades. The blades of these compound chaetae possess short, marginal spines which are longer on the most dorsal chaetae. ''Sphaerosyllis bardukaciculata'' shows four simple chaetae on the posterior parapodia. It counts with a single

acicula Acicula (: aciculum) are strong, stout internal chaeta A chaeta or cheta (; ) is a chitinous bristle or seta found on annelid worms, although the term is also frequently used to describe similar structures in other invertebrates such as art ...

, bent distally to a right angle. The pharynx spans approximately three segments. Its pharyngeal tooth is long, located on the anterior margin. Its proventricle spans through two segments, with 23

muscle cell A muscle cell, also known as a myocyte, is a mature contractile Cell (biology), cell in the muscle of an animal. In humans and other vertebrates there are three types: skeletal muscle, skeletal, smooth muscle, smooth, and Cardiac muscle, cardiac ...

rows. Its

pygidium The pygidium (: pygidia) is the posterior body part or shield of crustaceans and some other arthropods, such as insects and the extinct trilobites. In groups other than insects, it contains the anus and, in females, the ovipositor. It is compos ...

is small, with long

papilla Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Papilla (worms), small bumps on the surface of certain worms * Basilar papilla, a sensory organ of lizards, amphibians and fish * ...

e and two anal cirri.

Distribution

''Sphaerosyllis bardukaciculata'' was found in Halifax Bay, north of

Townsville The City of Townsville is a city on the north-eastern coast of Queensland, Australia. With a population of 201,313 as of 2024, it is the largest settlement in North Queensland and Northern Australia (specifically, the parts of Australia north of ...

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

at a depth of , and Heron Island, in

intertidal The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various sp ...

coarse sand. Its distribution is thought to include the whole of Queensland.

References

External links

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WORMS entry
{{Taxonbar, from=Q1993880 Syllidae Animals described in 2005

Description

Distribution

References

Further reading

External links