Fig 1.
Oscarella pearsei sp. nov. and O. carmela.
(A) In situ photographs of O. pearsei sp. nov. and (B) O. carmela. (C) Upon collection, these species can be distinguished based upon differences in their thickness, surface texture, and color. Left: O. pearsei sp. nov., Right: O. carmela. (photo credit: J. Mitchell, panel A).
Table 1.
Original O. carmela holotype and paratypes submitted to MNRJ.
Table 2.
Material source for genomic and transcriptomic data.
Fig 2.
Mitochondrial genome architecture.
Mitochondrial genome maps of Oscarella pearsei sp. nov. and O. carmela. Protein (green) and ribosomal (blue) genes are atp6, atp8-9: subunites 6, 8, and 9 of F0 adenosine triphosphatase (ATP) synthase; cob: apocytochrome b; cox 1–3: cytochrome c oxidase subunites 1–3; nad1-6 and nad4L: NADH dehydrogenase subunits 1–6 and 4L; rns and rnl: small and large subunit rRNAs; tatC: twin-arginine translocase component C. tRNA genes (black) are identified by the one-letter code for their corresponding amino acid. Genes outside the main circle are transcribed clock-wise, inside—counter clock-wise. Large inversion between two copies of trnV in O. pearsei sp. nov. mtDNA is shown in red.
Fig 3.
Homoscleromorph phylogenetic relationships inferred from ribosomal DNA and mitochondrial data.
Maximum likelihood analyses of SSU/LSU rDNA and Bayesian analysis of a mitochondrial supermatrix (4070 amino-acid positions derived from 14 mitochondrial protein-coding genes) for Oscarella and outgroup species. Support values reflect Approximate Likelihood Ratio Test and posterior probability values, respectively. The consistently supported clades to which O. carmela and O. pearsei belong are highlighted by pink and blue boxes, respectively.
Fig 4.
Oscarella pearsei sp. nov. TEM of cells and symbiotic bacteria.
(A) exopinacocyte; (B) endopinacocyte; (C) choanocytes; (D) apopylar cell; (E) apical part of choanocyte with glycocalyx layer; (F) basal parts of choanocyte and endopinacocyte with basement membrane. (Abbreviations: AG–Golgi apparatus, ap–apopylar cell, B–symbiotic bacteria, bb–basal body of flagellum, bm–basement membrane, ch–choanocytes, en–endopinacocyte, ex–exopinacocyte, f–flagellum, mv–microvilli, n–nucleus, ph–phagosome. Arrowheads–white: basal surface has pseudopodia that extend into the extracellular matrix. black: glycocalyx).
Fig 5.
Oscarella pearsei sp. nov. mesohylar cells.
(A) granular cell type 1; inset—detail of granule, scale bar = 0.5 μm; (B) spherulous cells with paracrystalline inclusions; inset—detail of granule, scale bar = 0.5 μm; (C) archeocyte; (D) symbiotic bacteria. (Abbreviations: B–symbiotic bacteria, g–granule, gp—granule with paracrystalline inclusions, n–nucleus, v–vacuole).
Fig 6.
Oscarella pearsei sp. nov. reproduction.
(A) semi-thin section of the spermatocyst; (B) TEM of young oocyte before vitellogenesis; (C) semi-thin section of the egg with flat monolayer follicle and the thick layer of maternal cells; (D) TEM of flat monolayer follicle of the egg and the thick layer of maternal cells; (E) semi-thin section of the embryo with bilayer follicle composed of cubical cells; (F) histological section of embryos with cubical follicle; (G) semi-thin section of the cinctoblastula larva; (H) TEM of the embryo with bilayer follicle with flat external layer and cubical internal ones. (Abbreviations: cc—choanocyte chamber, cf–cubic follicle, ch–choanocyte, eg–egg, em–embryo, en–endopinacocyte, ex–exhalant canal, ff–flat follicle, gc–granular cells; l–larva, lc–larval cavity, le–larval ciliated epithelium, mc–maternal cells; n–nucleus, oo- oocyte, sc–spherulous cells with paracrystalline inclusions, sp–spermatocyst).
Fig 7.
Oscarella carmela TEM of cells.
(A) exopinacocyte; (B) endopinacocyte; (C) choanocytes; (D) apopylar cell; (E) granular cell type 1; (F) differentiated granular cell type 2, Inset: granules with filamentous inclusions; (G) granular cell type 2 with small number of inclusions; (H) vacuolar cell with granular inclusions, Inset—granule. (Abbreviations: ap–apopylar cell, B1 –bacteria type 1, en–endopinacocyte, ex–exopinacocyte, f–flagellum, g–granule, mv–microvilli, n–nucleus, v–vacuole).
Fig 8.
Oscarella carmela TEM of symbiotic bacteria.
(A, B) associated bacteria type 1; (C, D) associated bacteria type 2.
Fig 9.
Oscarella carmela follicle and reproduction.
(A) semi-thin section of the egg with flat monolayer follicle; (B) semi-thin section of cleaving embryo with flat monolayer follicle; (C) semi-thin section of the embryo with flat monolayer follicle; (D) in vivo image of cinctoblastula larva; (E) TEM of flat monolayer follicle of the egg; (F) TEM of with flat monolayer follicle of the embryo; (G) spermatocyst; (H) detail of the spermatocyst with surrounding follicle epithelium, spermatogonia and the spermatids. (Abbreviations: B1 –bacteria type 1, B2 –bacteria type 2, bl–blastomeres; cc—choanocyte chamber, eg–egg, em–embryon, f–flagella, ff–flat follicle, l–larva, le–larval epithelium, n–nucleus, sf—follicle of a spermatocyst, sg—spermatogonia, st–spermatid, vc–vacuolar cell with granular inclusions).
Table 3.
The cytological characters of Oscarellidae species with cells that contain paracrystalline inclusions.