''Robertianella'' is a genus of marine
annelid
The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecol ...
s in the family
Polynoidae
Polynoidae is a family of marine Polychaete worms known as "scale worms" due to the scale-like elytra on the dorsal surface. Almost 900 species are currently recognised belonging to 9 subfamilies and 167 genera. They are active hunters, but gene ...
(scale worms). There are 2 species of ''Robertianella'' which are known from depths of about 600 to 3000 m in the north-east Atlantic Ocean and the Mediterranean Sea.
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Description
''Robertianella'' are short-bodied scale worms with 33 to about 43 segments and 15 pairs of
elytra
An elytron (; ; , ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs ( Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometimes altern ...
. The
prostomium
The prostomium (From Ancient Greek, meaning "before the mouth"; plural: prostomia; sometimes also called the "acron") is the cephalized first body segment in an annelid worm's body at the anterior end. It is in front of (but does not include) th ...
is bilobed anteriorly and each lobe has a small prominence ("cephalic peak") on the anterior margin. The lateral antennae are located ventrally, directly beneath median antenna ceratophore. The neuropodia are elongate and tapering. The
notochaetae
A chaeta or cheta (from Greek χαίτη “crest, mane, flowing hair"; plural: chaetae) is a chitinous bristle or seta found in annelid worms, (although the term is also frequently used to describe similar structures in other invertebrates such ...
are about as thick as the
neurochaetae and both are ornamented with transverse rows of small spines. The neurochaetae are distinctive, with minutely notched tips.
[Barnich R, Fiege D (2000) Revision of the Mediterranean species of Harmothoe Kinberg, 1856 and Lagisca Malmgren, 1865 Polychaeta: Polynoidae: Polynoinae) with descriptions of a new genus and a new species. Journal of Natural History 34: 1889–1938. https://doi.org/10.1080/00222930050144783]
Species
Two species of ''Robertianella'' are recognised as valid as of September 2020:
*''
Robertianella platychaeta'' Detinova, 1985
*''
Robertianella synophthalma'' McIntosh, 1885
References
{{Taxonbar, from=Q3916443
Phyllodocida
Polychaete genera