Table 1.
Sampling stations where D. antarctica and D. carinova Moles, Avila & Wägele n. sp. were collected.
Kapp Norvegia is situated in the eastern Weddell Sea.
Fig 1.
Photographs of D. antarctica (left column: A,C,E,G) and D. carinova Moles, Avila & Wägele n. sp. (right column: B,D,F,H); specimens subjected to micro-CT reconstruction.
A Live animal, where most of the cerata were lost; close up of the cerata. B Live picture right after collection, showing the D. carinova n. sp. spawning on top of the gorgonian Primnoisis antarctica (Isididae). C–D Lateral and dorsal view of the preserved animals. E–F Ventral view of the preserved animals. G–H Lateral view of the preserved egg masses.
Fig 2.
Micro-CT reconstructions of the internal organs of D. antarctica (left column) and D. carinova Moles, Avila & Wägele n. sp. (right column).
A–B Right antero-lateral view of all reconstructed organs. C–D Left antero-lateral view of the circulatory, digestive, excretory, and nervous systems. E–F Right lateral view of the male reproductive system. G–H Left lateral view of the reproductive system (mucus gland is not depicted here since it covers the whole view). am ampulla; adiv ampulla diverticulum; au auricle; bc bursa copulatrix; cis circulatory sinuses; cgl capsule gland; cpg cerebropleural ganglion; dg distal gonoduct; dgdiv digestive gland diverticula; dgl digestive gland (only depicted in D. carinova n. sp.); gc giant cells; gon gonad; ht heart; int intestine; kid kidney; megl membrane gland; mugl mucus gland; oes oesophagus; od odontophore; ot oral tube; ov oviduct; peg pedal ganglion; pen penis; per pericardium; pg proximal gonoduct; pha pharynx; pro prostate; rad radula; rhg rhinophoral ganglion; rhi rhinophore; rhs rhinophoral sheath; sgl salivary gland; sin sinus; sp sphincter; sto stomach; vag vagina; vd vas deferens; ven ventricle.
Fig 3.
Histological slides of the glandular structures in D. antarctica.
A Epidermis of the rhinophoral sheath. B Detail of one cerata tubercle showing defensive glandular cells (white punctuation in live animals). C Oral glands. D Giant neurones chain attached to the cerebropleural ganglion; a thin cortex, large nucleus, and nucleolus of each cell can be seen. E Detail of the prostate glandular cells. F Detail of the capsule glandular cells. G Detail of the membrane glandular cells. H Detail of the glandular mucus cells. gc giant cells; lum lumen; muc glandular mucus cell; n nucleus; nu nucleolus; ogl oral glands; pha pharynx; rhn rhinophoral nerve; sin sinus vessel; sgl salivary gland; smc specialised multivacuolised cell; wgc white glandular cells.
Fig 4.
Scanning electron micrographs (SEM) of the radular teeth of D. antarctica.
Fig 5.
Left antero-lateral view of the micro-CT reconstruction of the nervous system of D. carinova Moles, Avila & Wägele n. sp. cpg cerebropleural ganglion; gc giant cells; peg pedal ganglion; rhg rhinophoral ganglion; sin sinus.
Fig 6.
Histological slide of outer surface of the egg mass in Doto carinova Moles, Avila & Wägele n. sp.
Table 2.
Differential characters among D. carinova Moles, Avila & Wägele n. sp. and D. antarctica.
Fig 7.
Phylogenetic tree of Doto species based on the combined COI, 16S, and H3 genes using Bayesian inference (BI) and maximum-likelihood (ML).
Numbers on nodes indicate posterior probability values (BI) and bootstrap support values (ML). Specimens sequenced are in bold; Doto antarctica specimens are coloured in red. Schematic drawings of the reproductive system of Doto species are depicted (A–D), as well as the unsequenced D. uva Marcus, 1955 (E). bc bursa copulatrix; gd gonoduct; nigl nidamental glands; pen penis; rs receptaculum seminis; vd vas deferens.