Research Article |
Corresponding author: Jaime Gonzalez-Cueto ( biojaime14@hotmail.com ) Academic editor: Jon Norenburg
© 2017 Jaime Gonzalez-Cueto, Lyda R. Castro, Sigmer Quiroga.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Gonzalez-Cueto J, Castro LR, Quiroga S (2017) Nipponnemertes incainca sp. n. Adoption of the new taxonomic proposal for nemerteans (Nemertea, Cratenemertidae). ZooKeys 693: 1-15. https://doi.org/10.3897/zookeys.693.12015
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A new species Nipponemertesincainca is described from the intertidal zone of Santa Marta, Colombia. A new recent approach based on both morphological and molecular characters is applied for the description. The main characteristics of the species are: red color, head shield-shaped with a mid-dorsal cephalic ridge, furrows pre-cerebral inconspicuous with few faint ridges orthogonal to furrow axis, two irregular groups of eyespots situated at lateral margins in precerebral cephalic region, proboscis provided with papillae and 12 nerves, stylet smooth supported on an oval basis, and two pouches containing 3–4 accessory stylets each. The sequence of the COI gene was analyzed as an additional support for the new species.
New species, Nemertea , COI, Caribbean coast of Colombia
Nemerteans (phylum Nemertea), commonly known as ribbon worms or Rhynchocoela, comprise a cosmopolitan group of bilateral, coelomate, and unsegmented worms (
Of the 36 species of nemerteans documented for the Caribbean Sea (
Herein, the method proposed by
Four specimens were hand-collected on the rocky littoral from Inca-Inca Bay, Santa Marta, Colombia (11°12'30.2"N; 74°13'54.5"W). Individuals were relaxed in 7% MgCl2 solution isotonic to seawater and photographed “in vivo” with a digital camera Nikon D7100 with a 60 mm ED Micro-Nikkon lens. Details of morphological characters were photographed with a stereomicroscope Leica M205A with an integrated Camera Leica DFC450. Detailed images of the proboscis and stylets were obtained by pressing the specimens between a slide and a coverslip (obligating them to protrude the proboscis) and photographing them with a microscope Zeiss Axiolab A1 with an integrated camera Zeiss ERc5s. Two specimens were fixed in 100% ETOH for molecular purposes and two in 10% formalin for future morphological analysis.
Two additional specimens previously collected and deposited in the “Centro de Colecciones Biológicas de la Universidad del Magdalena, CBUMAG” (
Total DNA was extracted from one entire worm fixed in 100% ETOH, using the DNeasy Blood & Tissue® Kit following the manufacturer’s protocol (Qiagen, Valencia, CA, USA). The partial COI gene was amplified with universal primers described in
Holotype: COLOMBIA Santa Marta, Rodadero Inca-Inca beach (11°12'30.2"N, 74°13'54.5"W), intertidal zone under boulders, whole specimen in 70% ethanol (CBUMAG:NEM: 0056). Total body length 18.5 mm, 1 mm wide.
Paratypes: COLOMBIA Santa Marta, Taganga (11°15'51.23"N, 74°11'31.54"W), intertidal zone under boulders covered by sponges, whole specimen in 70% ethanol (CBUMAG:NEM: 0043). Total body length 11.7 mm, 1.8 mm wide.
COLOMBIA Santa Marta, Rodadero Inca-Inca beach (11°12'30.2"N, 74°13'54.5"W), intertidal zone under boulders, transverse histological sections of the proboscis; rest of specimen in 70% ethanol (CBUMAG:NEM:0049). Total body length 22.5 mm, 2.05 mm wide.
COLOMBIA Santa Marta, Rodadero Inca-Inca beach (11°12'30.2"N, 74°13'54.5"W), intertidal zone under boulders; tissue in absolute ethanol (CBUMAG:NEM:00068, CBUMAG:NEM:00069).
An entire additional worm, collected in Inca-Inca beach (11°12'30.2"N, 74°13'54.5"W) was used for DNA extraction. Sequence data for 615 bp of Cytochrome C Oxidase Subunit I deposited in GenBank under accession number KX879856 (see alignments with other congeners in supplemental information).
The specific epithet refers to the “Inca-Inca beach” site from which most of the specimens were collected; this name is in apposition.
Nipponnemertes incainca sp. n., like other members of Nipponnemertes, has a mid-dorsal cephalic ridge, is capable of retracting the head into the body when disturbed, and is capable of swimming. However, in this new species the anterior furrows and their secondary transverse grooves are faintly visible both macro- and microscopically and they are not visible in a ventral view.
Relaxed length from 11.7 mm to 22.5 mm and width 1 to 2 mm. Dorsal side uniformly bright red color (Fig.
Nipponnemertes incainca sp. n. A Transverse sections of the proboscis; nerves are highlighted by arrowheads B Microscopic detail of transverse section showing the proboscis papillae. Abbreviations: pp proboscis papillae, lm longitudinal muscles, cm circular muscles, rm retractor muscles of the proboscis, n nerve.
We compared morphological characters of Nipponnemertes incainca sp. n. with the 18 valid species of the genus, according to
The most similar species in color, arrangement of ocelli and numbers of proboscidial nerves to Nipponnemertes incainca sp. n. is N. pulchra and it might easily represent an intraspecific variation. However, in the intraspecific and interspecific genetic distance matrix (table 2), the interspecific distance between N. incainca sp. n. and N. pulchra was 21.03%, which exceeds the highest limits given by
Remarks about morphological and behavioral traits useful to discriminate the species of the genus Nipponnemertes. Reference after authority in species column.
Species | Body Coloration, | Number of Proboscis Nerves | Mid-dorsal cephalic ridge | Shape and distinctness of posterior dorsal V-shaped cephalic groove | Other Noteworthy Characters |
---|---|---|---|---|---|
Nipponnemertes incainca sp. n. | Solid bright red color pattern without designs | 12 | Present | Lacking | Anterior furrows and secondary transverse grooves present, but faintly visible both macro and microscopically. Inhabits rocky littoral zone |
Nipponnemertes africanus (Wheeler, 1940) Berg, 1985 | “White, pink, pinkish yellow or buff, lighter anteriorly and deepest on back” ( |
11 | Present ( |
Present. Two posterior dorsal cephalic grooves, V-shaped but not joined medially ( |
Faint head-glands, open close to external opening of rhynchodeum and disappear just before brain. Found between roots of alga Hypnea specifica, low on shore |
Nipponnemertes arenaria (Uschakov, 1927) |
Margins of body lighter in color | Inhabits muddy sand ( |
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Nipponnemertes bimaculatus (Coe, 1901) Gibson & Crandall, 1989 | Head flesh in color; rest of body is deep red, brownish red, or brownish orange; lighter on ventral surface. Possesses pair scalene triangle-shaped cephalic marks and a narrow longitudinal line of dark color on dorsal surface of esophageal region | 14 or 16 | Present ( |
Lacking | Central stylet very long and slender, mounted on a remarkably tiny base |
Nipponemertes danae (Friedrich, 1957) Friedrich, 1968 | Dorsal surface red, ventral white; color description based on Coe’s description of Nipponnemertes drepanophoroides ( |
Original description is vague and lacks important information. According to |
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Nipponnemertes drepanophoroides (Griffin, 1898) Friedrich, 1968 | Red above, white beneath | Lacks intestinal caeca | |||
Nipponnemertes fernaldi Iwata, 2001 | Pale brown on dorsal surface and darker on the ventral side (colorless lateral margins) | 14 | Present | Oblique, limited to dorsal surface | |
Nipponnemertes madagascarensis (Kirsteuer, 1965) Friedrich, 1968 | Ochre on dorsal surface, stained with irregular reddish-brown blotches | 9 | Lacking | Lacking | |
Nipponnemertes magnus (Punnett, 1903) Berg, 1985 | Light orange-brown | 20 | |||
Nipponnemertes marioni (Hubrecht, 1887) Berg, 1985 | “Dorsally blue-green, yellow-green, pale buff or light brown, and ventrally pale buff light orange-brown” ( |
15 | |||
Nipponnemertes occidentalis (Coe, 1905) Friedrich, 1968 | Blotchy dark reddish brown or pale ground color throughout whole dorsal surface, and “ventral surface without color” ( |
Highly developed intestinal caecum. Caecal appendage in esophagus and one in stomach | |||
Nipponnemertes ogumai (Yamaoka, 1947) |
Uniformly orange ( |
16 | Present ( |
Present, but not significantly developed | Minute ocelli gathered as a triangle on each side of head |
Nipponnemertes pacificus (Coe ,1905) Friedrich, 1968 | Reddish or brownish dorsal surface, pale beneath | 14 | Lacking | Lacking | Cerebral sense organs remarkably large and highly specialized. Highly developed esophageal caecum ( |
Nipponnemertes pulchra (Johnston, 1837) Berg, 1972 | “Dorsal surface varying between brown, red and pink. Lateral parts of body and ventral surface always much lighter, longitudinal dorsal swelling on head often somewhat darker” ( |
8-14 (normally 12) | Present | Dorsally, clearly marked and darker than rest of body. Does not reach midline on ventral surface | Presence of accessory stylet in basis of central armature. This character has been highlighted as one of best criteria to recognize N. pulchra |
Nipponnemertes punctatulus (Coe, 1905) Friedrich, 1968 | Pale brown or yellowish white with numerous darker brown spots on dorsum and white ventrum (head white with two dark blotches). Proboscis transparent, with pinkish stylet basis ( |
15 | Present | Lacking |
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Nipponnemertes rubella (Coe, 1905) Crandall & Norenburg, 1999 | Deep flesh color, pale orange, or pale red; much paler and usually grayish beneath | 14 | Great development of body parenchyma and intestinal caeca | ||
Nipponnemertes sanguinea Riser, 1998 | Dorsum buffy white to pale yellow to orange with reddish lines (aggregation of red blood corpuscles in blood vessels), ventral side paler, brain lobes pink | 12 | “Not evident” ( |
Lacking | Presence of red blood corpuscles |
Nipponnemertes schollaerti (Wheeler, 1934) Berg, 1985 | Pale buff color | 14 | Lacking ( |
Lacking | |
Nipponnemertes variabilis (Korotkevich, 1983) Chernyshev, 1993 | Beige dorsal and ventrally | 12-13 | Lacking | Separating strongly head from rest of body |
COI-based matrix of interspecific and intraspecific genetic distances, using Kimura’s two-parameter model K2P (Kimura 1980). GenBank accession numbers: Nipponnemertes incainca sp. n. (KX879856); N. bimaculatus (AJ436909); N. pulchra (KP697761- KP697767); N. punctatulus (AJ436910); N. ogumai (AB920907); Nipponnemertes sp. 1 (HQ848598); Nipponnemertes sp. 2 (HQ848599); Nipponnemertes sp. 3 (KU230295).
Nipponnemertes incainca sp. n. | Nipponemertes bimaculatus | Nipponnemertes pulchra | Nipponnemertes punctatulus | Nipponnemertes ogumai | Nipponnemertes sp. 1 | Nipponnemertes sp. 2 | Nipponnemertes sp. 3 | |
---|---|---|---|---|---|---|---|---|
Nipponnemertes incainca sp. n. | × | × | × | × | × | × | × | × |
Nipponemertes bimaculatus | 15.62 | × | × | × | × | × | × | × |
Nipponnemertes pulchra | 21.03 | 20.12 | 0.09 | × | × | × | × | × |
Nipponnemertes punctatulus | 17.13 | 8.61 | 18.39 | × | × | × | × | × |
Nipponnemertes ogumai | 56.60 | 53.33 | 48.44 | 55.31 | × | × | × | × |
Nipponnemertes sp. 1 | 21.44 | 19.14 | 4.50 | 18.31 | 52.26 | × | × | × |
Nipponnemertes sp. 2 | 16.00 | 18.82 | 10.32 | 18.91 | 47.30 | 10.92 | × | × |
Nipponnemertes sp. 3 | 17.13 | 8.61 | 18.39 | 0.00 | 55.31 | 18.31 | 21.00 | × |
Approximately, 2.2 million (σ 0.18) species inhabit the marine ecosystems, yet 91% of these still await description (
Nipponnemertes incainca sp. n. was recorded as Cratenemertidae sp. by
Character checklist. List of external characters that could be checked in order to provide a species description with comparable characters. Modified from
Character | Character state | Code | |
---|---|---|---|
1. | Biology | Free-living | 0 |
2. | Habitat | Marine | 0 |
3. | Benthic divisions | Littoral | 1 |
5. | Habitat | Epibenthic | 2 |
6. | Substratum | Rock/boulders | 3 |
7. | Behavior when mechanically disturbed | Contracts without coiling into a spiral | 0 |
External morphology | |||
8. | Cephalic furrows/slits | One pair | 1 |
9. | Distribution of anterior cephalic furrows/slits | Dorsal | 1 |
10. | Shape of anterior (dorsal) cephalic furrows (viewed with tip of head directing forwards) | Ventral transversal | 2 |
12. | Head clearly demarcated from body | Head not wider than trunk | 2 |
13. | Position of cephalic furrows | If single pair in front of brain lobes | 1 |
14. | Shape of head/cephalic lobe | Shield-shaped | 10 |
15. | Head viewed laterally | Without extensions | 0 |
16. | Cross section shape of body | Rounded cylindrical | 0 |
17. | Shape of posterior tip | Bluntly rounded | 3 |
18. | Eyes | Eyes arranged in lateral rows or groups on each side of head | 7 |
19. | Eye distinctiveness | Eyes visible from ventral side | 0 |
20. | Eye morphology | Simple | 0 |
21. | Relative eye size | All eyes more or less of equal size | 0 |
22. | Eye position relative to brain lobes | Confined principally or entirely to precerebral cephalic region but may extend back to above brain | 0 |
23. | General body color | No obvious color | 0 |
24. | Primary dorsal body color | Red | 0 |
25. | Color pattern | Absent | 0 |
26. | Color of blood | Red | 0 |
27. | Proboscis armature | With central and accessory stylets | 2 |
28. | Number of accessory stylet pouches | Two | 0 |
29. | Number of stylets in each accessory stylet pouch | Three or four | 1 |
30. | Stylet : basis/stylet ratio | 1.5:1 | 1 |
31. | Stylet shaft | Smooth and straight | 0 |
32. | Shape of stylet basis | Oval (rounded) | 0 |
33. | Median waist of stylet basis | Absent | 0 |
34. | Proboscis used for locomotion | Yes | 1 |
35. | Proboscis pore | Subterminal, ventral | 1 |
38. | Lateral margins | No distinction in color | 1 |
39. | Distribution of bristles/cirri | Only on head | 1 |
We are thankful to Daniel Cubillos, Darlin Botto, Maria Victoria León, Pedro Prado, Roberto Guerrero, and Tania Franco for their help in collecting, imaging processing and molecular disscusions. Special thanks to Dra. Marcela Bolaños and Joseph Dunn for proof-reading the manuscript, and to the editor of the journal, Dr. Jon Norenburg, who kindly improved both the English and the scientific content of the paper and helped us with the preliminary identification of the species. We are particularly indebted to Dr. Jörn von Döhren, Dr. Malin Strand and an anonymous reviewer for their constructive comments on the manuscript. This study was partially supported by Departamento Administrativo de Ciencia, Tecnología e Innovación. COLCIENCIAS under the program Convocatoria para la formación de capital humano de alto nivel para el departamento del Magdalena-2014 (convocatoria 672 Cap. 3, Maestría nacional), Fundación Para la Investigación, Conservación y Desarrollo Sostenible de Socio-Ecosistemas and the Fundación Alejandro Ángel Escobar. This is a contribution No. 6 from the Centro de Colecciones Biológicas de la Universidad el Magdalena CBUMAG.
COI partial gene alignments of all Nipponnemertes sequences from GenBank
Data type: molecular data
Explanation note: Fasta format