Tritonidoxa Bergh 1907

Silva, Felipe De Vasconcelos, Pola, Marta & Cervera, Juan Lucas, 2023, A stomach plate to divide them all: a phylogenetic reassessment of the family Tritoniidae (Nudibranchia: Cladobranchia), Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 199 (2), pp. 445-476 : 465

publication ID	https://doi.org/ 10.1093/zoolinnean/zlad013
publication LSID	lsid:zoobank.org:pub:C3E2DFF9-A0A6-41EA-A149-0F73A2BEE5E6
DOI	https://doi.org/10.5281/zenodo.8426089
persistent identifier	https://treatment.plazi.org/id/03A6878C-FF84-6503-FC81-FDA4EC08F9BF
treatment provided by	Plazi
scientific name	Tritonidoxa Bergh 1907
status

Treatment

Tritonidoxa Bergh 1907 View in CoL ( Figs 3D View Figure 3 , 4D View Figure 4 , 5D View Figure 5 , 6D View Figure 6 )

Type species: Tritonidoxa capensis Bergh 1907 , by original designation. To date, this is a monotypic genus.

Diagnosis: Penis long, spiralled with pointed end. Secondary gills abscent; notal margin distinct, broad and wrinkled.

Morphology: Body slightly broad, length up to 32 mm. Notum smooth, with transverse white patches from head to tail. Oral veil narrow and entire. Eight simple velar processes. Secondary gills absent. Notal margin distinct, broad and wrinkled ( Fig. 3D View Figure 3 ). Ratio jaw/body length: 0.20–0.35. Rachidian tooth tricuspid and smooth with a rectangular base ( Fig. 4D View Figure 4 ). First lateral tooth differentiated, broad, smooth and sharp. Masticatory borders of jaws denticulate, with medium-sized (up to 40 µm) denticles with conical bases and sharp cusps. Cuticular folds absent. ODG complex holohepatic ( Fig. 5D View Figure 5 ). Gonopore at one-third of body length, furthest from rhinophores. Anus and nephroproct aħer middle of body length. Bursa copulatrix reniform. Penis flagelliform long (up to 30 mm), spiralled with pointed end ( Fig. 6D View Figure 6 ). Ampulla slightly pyriform ( Fig. 6D View Figure 6 ).

Remarks: For the first time since its description, the monotypic species Tritonidoxa capensis is reassessed, and its taxonomic validity confirmed. Tritonidoxa was recovered as the sister-taxon of Tritonicula ( PP = 1; BS = 98) ( Fig. 2 View Figure 2 ), but the two genera are morphologically different: Tritonicula species. are smaller and have a distinct first lateral tooth and reproductive morphology. The morphological synapomorphies of Tritonidoxa are the spiralled, long penis (up to 30 mm) with a pointed end ( Fig. 6D View Figure 6 ) and absence of secondary gills, with the notal margin distinct, broad and wrinkled. To date, there is no further knowledge about the distribution and ecology of this aberrant species.