Scott & Jeanette Johnson, Kwajalein Unterwater
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Goniodoridella geminae Paz-Sedano, Ekimova, Smirnoff, Gosliner & Pola, 2023
New molecular sequencing, Paz-Sedano, Ekimova et al., 2023, has revealed that Goniodoridella savignyi is actually a clade of cryptic species. Three new species of Goniodoridella were identified: Goniodoridella geminae, Goniodoridella unidonta and Goniodoridella serrata cryptic with Goniodoridella savignyi (Pruvot-Fol, 1933) and the previously described Goniodoridella borealis Martynov, Sanamyan & Korshunova, 2015.
Goniodoridella geminae is a small species, up to 6 mm long. The body is elongated with a long and tapered tail. The body, mantle and foot are supported by a dense network of spicules. The mantle is broad and covers the body and foot, but not the tail.
The notal margin of the mantle is well developed and bears a series of small, pointed tubercles supported by spicules but not papillae. Small tubercles are present on the mantle, forming a midline ridge and extending from the rhinophores posteriorly to the gills.
The non-retractile rhinophores are smooth and slender. In front of each rhinophore there is a prominent, conical papilla of medium length on the anterior notal margin. The gill branches form a semicircle around the anus. There are usually four gill branches, the two central, anterior ones sharing a common stalk. Behind and lateral to the gill branches are two elongated, pointed and well-developed extrabranchial papillae, which have the same sausage-like shape and size as the gill branches.
The mantle, body, foot, tail, rhinophores, gill branches, papillae and tubercles are covered with white pigment. The white pigment covering is mostly opaque, sometimes with glassy patches. The rhinophores, anterior and posterior papillae, branchial branches, tail tip, and tubercles on the midline crest are all mostly yellow-tinted, but there are exceptions.
As with all Goniodoridella, the diet is thought to consist of bryozoans.
Goniodoridella geminae closely resembles Goniodoridella savignyi and Goniodoridella unidonta in shape and coloration, making confident identification very difficult.
The following distinguishing features are known:
Although most external features of this cryptic clade are shared with its conspecifics, they can be distinguished from each other as follows:
Goniodoridella geminae has branchial branches and extrabranchial papillae that are all sausage-shaped and of equal size.
Goniodoridella savignyi has extrabranchial papillae that are much larger than the branchial branches.
Goniodoridella borealis has three yellow longitudinal rows on the mantle.
Goniodoridella unidonta has extrabranchial papillae that are very broad at their base, giving them a somewhat triangular shape.
Goniodoridella serrata is essentially translucent white throughout, with a mantle margin that is strongly serrated and extrabranchial papillae that are short and pointed.
New molecular sequencing, Paz-Sedano, Ekimova et al., 2023, has revealed that Goniodoridella savignyi is actually a clade of cryptic species. Three new species of Goniodoridella were identified: Goniodoridella geminae, Goniodoridella unidonta and Goniodoridella serrata cryptic with Goniodoridella savignyi (Pruvot-Fol, 1933) and the previously described Goniodoridella borealis Martynov, Sanamyan & Korshunova, 2015.
Goniodoridella geminae is a small species, up to 6 mm long. The body is elongated with a long and tapered tail. The body, mantle and foot are supported by a dense network of spicules. The mantle is broad and covers the body and foot, but not the tail.
The notal margin of the mantle is well developed and bears a series of small, pointed tubercles supported by spicules but not papillae. Small tubercles are present on the mantle, forming a midline ridge and extending from the rhinophores posteriorly to the gills.
The non-retractile rhinophores are smooth and slender. In front of each rhinophore there is a prominent, conical papilla of medium length on the anterior notal margin. The gill branches form a semicircle around the anus. There are usually four gill branches, the two central, anterior ones sharing a common stalk. Behind and lateral to the gill branches are two elongated, pointed and well-developed extrabranchial papillae, which have the same sausage-like shape and size as the gill branches.
The mantle, body, foot, tail, rhinophores, gill branches, papillae and tubercles are covered with white pigment. The white pigment covering is mostly opaque, sometimes with glassy patches. The rhinophores, anterior and posterior papillae, branchial branches, tail tip, and tubercles on the midline crest are all mostly yellow-tinted, but there are exceptions.
As with all Goniodoridella, the diet is thought to consist of bryozoans.
Goniodoridella geminae closely resembles Goniodoridella savignyi and Goniodoridella unidonta in shape and coloration, making confident identification very difficult.
The following distinguishing features are known:
Although most external features of this cryptic clade are shared with its conspecifics, they can be distinguished from each other as follows:
Goniodoridella geminae has branchial branches and extrabranchial papillae that are all sausage-shaped and of equal size.
Goniodoridella savignyi has extrabranchial papillae that are much larger than the branchial branches.
Goniodoridella borealis has three yellow longitudinal rows on the mantle.
Goniodoridella unidonta has extrabranchial papillae that are very broad at their base, giving them a somewhat triangular shape.
Goniodoridella serrata is essentially translucent white throughout, with a mantle margin that is strongly serrated and extrabranchial papillae that are short and pointed.
