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Figure 14 in Character-matrix based descriptions of two new nemertean (Nemertea) species

Figure 14. Schematic representation of the proboscis apparatus showing proboscis nerves. Abbreviations: P, proboscis; PN, proboscis nerves; PNS, peripheral neural sheath; R, rhynchocoel; SPN, secondary proboscis nerves.

Figure 15 in Character-matrix based descriptions of two new nemertean (Nemertea) species

Figure 15. Schematic view of transverse section through the intestinal region of a nemertean to show the various organ systems mentioned in the character matrix list. The dashed lines show distribution of intestinal diverticulae alternating with the reproductive system. Abbreviations: Layers and structures of the body wall: E, epidermis; D, dermis; CM, circular muscle layer; LM, longitudinal muscle layer; PA, parenchyma. Proboscis apparatus: R, rhynchocoel; PM, proboscis retractor muscle. Alimentary system: I, intestine; IE, intestinal epithelium; SID, shallow intestinal diverticula; DID, deep intestinal diverticula. LN, lateral nerve cord; LV, lateral blood vessel. Reproductive system: G, gonad; O, ovary; OC, ovocyte; N, nucleolus; GD, gonoduct; GP, gonopore.

Figure 10 in Character-matrix based descriptions of two new nemertean (Nemertea) species

Figure 10. Schematic views of different cephalic furrows. A, ventral transversal furrows; B, small arches; C, posterior transversal furrow; D, lateral horizontal furrows; E, V-shaped furrows with secondary grooves (ghosted furrows show ventral distribution). See also Fig. 8.

Figure 9 in Character-matrix based descriptions of two new nemertean (Nemertea) species

Figure 9. Nemertean head shapes, cephalic furrows, and eye distribution. A, Nemertopsis flavida with two pairs, anterior and posterior, cephalic furrows and eyes in rectangle; B, Oerstedia dorsalis with eyes in square; C, Callinera monensis; D, Amphiporus bioculatus with anterior V-shaped and posterior L-shaped cephalic furrows. However, different authors have described the furrows of this species in other ways (McIntosh, 1873–74). Also note the two eyes at the anterior tip of the head; E, Tetrastemma cephalophorum; F, general representation of truncated head shape; G, Tubulanus inexpectatus; H, Amphiporus dissimulans with anterior and posterior U-shaped cephalic furrows. Also note the eyes arranged in lateral rows on each side of head; I, Nipponnemertes pulchra with secondary grooves of anterior cephalic furrows. Eyes as H; J, Tetrastemma flavidum; K, Prosorhochmus claparedii, note the distinct anterior eyes. (Redrawn from Gibson, 1974.)

Figure 7 in Character-matrix based descriptions of two new nemertean (Nemertea) species

Figure 7. Phylogeny of a selected number of palaeonemertean taxa to show the position of the new species described here (in bold). Majority rule consensus tree from a Bayesian analysis based on COI mtDNA sequences. Numbers above branches refer to a posteriori probabilities (only values> 95% reported). Outgroup species is Emplectonema neesii.

Figure 6. A–E in Character-matrix based descriptions of two new nemertean (Nemertea) species

Figure 6. A–E. Carinina ochracea sp. nov. A, section through cephalic region showing cerebral ganglion and intra-epithelial muscle fibre network. B, section through stomach region showing proboscis and body wall muscle layers. Note the rhynchocoelic villus (arrowhead). C, section through intestinal region showing rhynchocoelic caecum (arrowhead). D, section through intestinal region showing the excretory system. E, section through gonad region of body showing intestine and ova with nucleus (arrowhead). Abbreviations: CG, cerebral ganglion; CM, outer circular muscle layer; D, dermis; E, epidermis; F, follicle; GD, gonoduct; I, intestine; ICM, inner circular muscle; IEMN, intra-epithelial muscle fibre network; LM, longitudinal muscles; LN, lateral nerve cord; LV, lateral blood vessel; MF, muscle fibre; OV, ovum; P, proboscis; PN, protonephridia; R, rhynchocoel; RY, rhynchodaeum; S, stomach.

Figure 4. A–F in Character-matrix based descriptions of two new nemertean (Nemertea) species

Figure 4. A–F, Raygibsonia bergi gen. et sp. nov. A, section through anterior-most part of body showing cephalic glands, cerebral organs, oesophagus, and the poorly developed precerebral septum. B, section through cephalic region showing cephalic blood supply, stomach, and cerebral ganglia. Note the vascular plug (arrowhead). C, section through pyloric region showing the connection between pylorus and intestine. Note the myofibrillae in the lateral nerve cord (arrowhead) and the nerves of the proboscis (arrow). D, section through proboscis armature region of body showing the stylet apparatus. Note the accessory stylet (arrow) and the peripheral neural sheath (arrowhead) that connect the proboscis nerves. E, section through gonad region of body showing immature gonads (probably sac-like). Note the accessory lateral nerve (arrowhead). F, section through stomach region of body, showing distribution of gland cells. Abbreviations: AP, accessory stylet pouch; AN, accessory lateral nerve; CB, cerebral ganglion; CC, cerebral canal; CF, cephalic furrow; CG, cephalic glands; CL, dorsal lobules of cephalic glands; CM, circular muscle layer; CO, cerebral organ; D, dermis; DC, dorsal commissure; DG, dorsal ganglion; E, epidermis; ECF, cephalic gland encircling the foregut; G, gonad; I, intestine; IC, intestinal caecum; LD, lateral diverticula; LM, longitudinal muscle layer; LN, lateral nerve cord; LV, lateral blood vessel; MDV, mid-dorsal vessel; OE, oesophagus; P, proboscis; PE, proboscis epithelium; PN, proboscis nerve; PS, precerebral septum; PY, pylorus; R, rhynchocoel; RM, retractor muscle; S, stomach; SB, stylet basis; VG, ventral ganglion.

Figure 3 in Character-matrix based descriptions of two new nemertean (Nemertea) species

Figure 3. Raygibsonia bergi gen. et sp. nov. Drawing by Helena Samuelsson, The Encyclopedia of the Swedish Flora and Fauna.

Figure 16 in Character-matrix based descriptions of two new nemertean (Nemertea) species

Figure 16. General scheme of the transverse section through the brain region of a nemertean to show the various organs and tissues mentioned in the character matrix. Abbreviations: Layers and structures of the body wall. E, epidermis; D, dermis; CM, circular muscle layer; LM, longitudinal muscle layer; CF, cephalic furrow. Nervous system and sensory organs: DG, dorsal ganglion; VG, ventral ganglion; VC, ventral commissure; DC, dorsal commissure; NC, neurochord cell; ST, statocyst; CO, cerebral organ; CC, ciliated cerebral canal; FCC, forked cerebral canal; CG, dorsolateral extensions of cephalic glands; CL, cephalic lacuna; S, stomach.

Figure 1 in Character-matrix based descriptions of two new nemertean (Nemertea) species

Figure 1. Phylogeny of a selected number of nemertean taxa to show the position of the two new species described here (in bold). Majority rule consensus tree from a Bayesian analysis based on 18S rDNA sequences. Numbers above branches refer to a posteriori probabilities (only values> 95% reported). Three phoronid species were used as outgroup: Phoronis vancouverensis, Phoronis australis, Phoronis hippocrepia.

Figure 2 in Character-matrix based descriptions of two new nemertean (Nemertea) species

Figure 2. Phylogeny of a selected number of hoplonemertean taxa to show the position of the new hoplonemertean species described here (in bold). Majority rule consensus tree from a Bayesian analysis based on COI mtDNA sequences. Numbers above branches refer to a posteriori probabilities (only values> 95% reported). Outgroup species is Reptant nemertean sp500 (from Thollesson & Norenburg, 2003).

Fig. 11. A–G in Cutting the ribbon: bathyal Nemertea from seeps along the Costa Rica margin, with descriptions of 2 new genera and 9 new species

Fig. 11. A–G. Tetrastemma sundbergi sp. nov., holotype (SIO-BIC N256), transverse histological sections. H–M. Tetrastemma strandae sp. nov., holotype (SIO-BIC N285), horizontal histological sections (H–I) and transverse histological sections (J–M). A. Anterior tip of head with proboscis pore. B. Brain region with well-visible cerebral canal (arrowhead). C. Proboscis with 10 proboscis nerves (arrowheads) in stomach region. D. Pyloric region. E. Intestinal region with ovaries. F. Anterior part of lateral nerve cord. G. Posterior part of lateral nerve cord located in body wall musculature. H. Longitudinal section through anterior tip with proboscis pore. I. Longitudinal section through the ventral part of the anterior tip. J. Intestinal region with testes. K. Proboscis in stomach region with 10 proboscis nerves (arrowheads). L. Proboscis armature. M. Lateral nerve cord in intestinal region. Abbreviations: ap = accessory stylet pouch; as = accessory stylet; br = brain; cc = cerebral canal; cg = cephalic glands; cm = circular muscle layer; co = cerebral organ; dl = dorsal brain lobe; ec = excretory canal; i = intestine; ic = intestinal cecum; lb = lateral blood vessel; lm = longitudinal muscle layer; ln = lateral nerve cord; mv = mid-dorsal-vessel; o = ovary; p = proboscis; pe = proboscis epithelium; pp = proboscis pore; py = pylorus; rc = rhynchocoel; sb = stylet basis; t = testis; vc = ventral commissure; vl = ventral brain lobe. Scale: 100 µm.

Fig. 10. A–G in Cutting the ribbon: bathyal Nemertea from seeps along the Costa Rica margin, with descriptions of 2 new genera and 9 new species

Fig. 10. A–G. Alvinonemertes dariae gen. et sp. nov., holotype (SIO-BIC N281), transverse histological sections. H–N. Alvinonemertes claudiae gen. et sp. nov., holotype (SIO-BIC N283), transverse histological sections. A. Anterior tip of head with proboscis pore. B. Brain region. C. Anterior brain region with cerebral canal (arrowhead). D. Stomach region with excretory canal. E. Posterior body region with testes. F. Lateral nerve cord with accessory nerve in stomach region. G. Proboscis armature, accessory stylet pouches with accessory stylets. H. Anterior tip of head with proboscis pore. I. Region anterior to cerebral ganglia with well-visible cerebral canal (arrowhead). J. Anterior brain region. K. Pyloric region. L. Proboscis and mid-dorsal vessel in stomach region. M. Proboscis armature, circular basis of central stylet. N. Proboscis armature, accessory stylet pouches with accessory stylets. Abbreviations: an = accessory nerve; ap = accessory stylet pouch; as = accessory stylet; bl = blood vessel; br = brain; cg = cephalic glands; cm = circular muscle layer; co = cerebral organ; dl = dorsal brain lobe; ec = excretory canal; gd = gonoduct; i = intestine; ic = intestinal cecum; ip = intestinal pouches; lm = longitudinal muscle layer; ln = lateral nerve cord; mv = mid-dorsal vessel; p = proboscis; pe = proboscis epithelium; pp = proboscis pore; py = pylorus; rc = rhynchocoel; rd = rhynchodaeum; sb = stylet basis; st = stomach; t = testis; vl = ventral brain lobe. Scale bars: A–G = 100 µm; H–N = 30 µm.

Fig. 8 in Cutting the ribbon: bathyal Nemertea from seeps along the Costa Rica margin, with descriptions of 2 new genera and 9 new species

Fig. 8. Live images of eumonostiliferous hoplonemerteans collected along the Costa Rica margin and the NE Pacific. A. Chernyshevia escarpiaphila sp. nov., paratype (SIO-BIC N112). B. Chernyshevia escarpiaphila sp. nov., paratype (SIO-BIC N266). C. Octocoral Paragorgia sp. (SIO-BIC Co3054) with several specimens of Alvinonemertes dariae sp. nov., holotype (arrows; ex SIO-BIC N262). D. Alvinonemertes dariae sp. nov., holotype (ex SIO-BIC N262).E. Antipatharian coral (SIO-BIC Co3031) with specimens of Alvinonemertes dagmarae sp. nov., holotype (SIO-BIC N260). F. Alvinonemertes christianeae sp. nov., holotype (SIO-BIC N253). G. Alvinonemertes claudiae sp. nov., holotype (ex SIO-BIC N231). H. Alvinonemertes tatjanae sp. nov., holotype (SIO-BIC N119). I. Eumonostilifera (SIO-BIC N259). J–L. Tetrastemma sundbergi sp. nov., holotype (SIO-BIC N256) whole animal (J), dorsal view of head (K), and ventral view of head (L). M. Tetrastemma polyakovae sp. nov. (MZUCR Nemertea Collection MZUCR-101-01). N. Tetrastemma polyakovae sp. nov., holotype (SIO-BIC N258), with everted proboscis. O. Eumonostilifera (SIO-BIC N109).

Fig. 7 in Cutting the ribbon: bathyal Nemertea from seeps along the Costa Rica margin, with descriptions of 2 new genera and 9 new species

Fig. 7. Maximum likelihood (ML) tree for the monostiliferan supermatrix based on the concatenated four gene dataset (16S, COI, 18S, H3). Black circles indicate nodal support of 100/100/1.0; asterisks indicate nodal support of either 100/ or /1.0. Alternative branches found in the BI analysis are given as blue dotted lines. Sonnenemertes cantelli Chernyshev, Abukawa & Kajihara, 2015 and Micrura callima Sundberg & Gibson, 1995 were used for outgroup rooting. Specimens belonging to new species are given in bold. Specimen-ID, sampling locality, and depth (for deep-sea species) are provided.

Fig. 6 in Cutting the ribbon: bathyal Nemertea from seeps along the Costa Rica margin, with descriptions of 2 new genera and 9 new species

Fig. 6. Maximum likelihood (ML) tree for the polystiliferan supermatrix based on the concatenated four gene dataset (16S, COI, 18S, H3). Black circles indicate nodal support of 100/100/1.0; asterisks indicate nodal support of either 100/ or /1.0. Alternative branches found in the BI analysis are given as blue dotted lines. Sonnenemertes cantelli Chernyshev, Abukawa & Kajihara, 2015 and Micrura callima Sundberg & Gibson, 1995 were used for outgroup rooting. The reptant hoplonemertean specimen collected at the Costa Rica margin is given in bold. Specimen-ID, sampling locality, and depth (for deep-sea species) are provided.

Fig. 5 in Cutting the ribbon: bathyal Nemertea from seeps along the Costa Rica margin, with descriptions of 2 new genera and 9 new species

Fig. 5. Maximum likelihood (ML) tree for the heteronemertean supermatrix based on the concatenated four gene dataset (16S, COI, 18S, H3). Numbers beside nodes indicate support values. Black circles indicate nodal support of 100/100/1.0; asterisks indicate nodal support of either 100/ or /1.0. Alternative branches found in the BI analysis are given as blue dotted lines. Tubulanus polymorphus Renier, 1804 and Carinoma mutabilis Griffin, 1898 were used for outgroup rooting. The specimen found at the Costa Rica margin is given in bold. Specimen-ID, sampling locality, and depth (for deep-sea species) are provided.

Fig. 4 in Cutting the ribbon: bathyal Nemertea from seeps along the Costa Rica margin, with descriptions of 2 new genera and 9 new species

Fig. 4. Tubulanus cf. lutescens Cantell, 2001 (SIO-BIC N277), transverse histological sections. A. Anterior region of head with proboscis pore. B. Posterior brain region with mouth opening and buccal nerves (arrowheads). C. Proboscis composition and the two proboscis nerves (arrowheads) in the foregut region. D. Brain region showing the cerebral canal. E. Body wall composition in the foregut region, arrowhead indicates upper dorsal nerve. F. Lateral nerve cord in the foregut region. Abbreviations: br = brain; cc = cerebral canal; cl = cephalic loop; dl = dorsal brain lobe; e = epidermis; es = esophagus; icm = inner circular muscle layer; lb = lateral blood vessel; lm = longitudinal muscle layer; ln = lateral nerve cord; mo = mouth opening; ocm = outer circular muscle layer; p = proboscis; pcm = circular musculature of proboscis; pcn = precerebral nerves; pe = proboscis epithelium; plm = longitudinal musculature of proboscis; pp = proboscis pore; rc = rhynchocoel; rcm = circular musculature of rhynchocoel; vc = ventral commissure; vl = ventral brain lobe. Scale bars: A–C, E = 200 µm; D, F = 100 µm.

Fig. 1. Sampling sites along the Costa Rica margin and exemplary habitat pictures. A in Cutting the ribbon: bathyal Nemertea from seeps along the Costa Rica margin, with descriptions of 2 new genera and 9 new species

Fig. 1. Sampling sites along the Costa Rica margin and exemplary habitat pictures. A. Map of the seven sampling sites along the Costa Rica margin: Cocos Canyon (CC), Jaco Scar (JS), Mound 11 (M11), Mound 12 (M12), Mound Jaguar (MJ), Parrita Seep (PS), and Quepos Plateau (QP). B. Aggregation of the vestamentiferan Escarpia spicata Jones, 1985. C. Nemerteans of the species Chernyshevia escarpiaphila sp. nov. (arrows) found on Escarpia spicata. Photo credit: ROV SuBastian/Schmidt Ocean Institute.

Fig. 2 in Cutting the ribbon: bathyal Nemertea from seeps along the Costa Rica margin, with descriptions of 2 new genera and 9 new species

Fig. 2. Maximum likelihood (ML) tree for the palaeonemertean supermatrix based on the concatenated four gene dataset (16S, COI, 18S, H3). Numbers beside nodes indicate support values. Black circles indicate nodal support of 100/100/1.0; asterisks indicate nodal support of either 100/ or /1.0. Alternative branches found in the BI analysis are given as blue dotted lines. Sonnenemertes cantelli Chernyshev, Abukawa & Kajihara, 2015 and Micrura callima Sundberg & Gibson, 1995 were used for outgroup rooting. Specimens belonging to the new species Tubulanus cf. lutescens are highlighted in bold. When available a specimen-ID, sampling locality, and depth (for deep-sea species) are provided. A statistical parsimony haplotype network based on the COI gene fragment reveals close relationship between Tubulanus cf. lutescens and Tubulanus lutescens.