Key:  Phylum Nemertea

Taken primarily from  Kozloff, 1987, 1996 p. 95 (Copyright 1987, 1996, University of Washington Press.  Used in this web page by permission of University of Washington Press)
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1a  Mouth separate from the proboscis pore, and both openings located on the ventral side of the head posterior to the brain; proboscis without stylets (Class Anopla) 2
1b Mouth united with the proboscis pore, the single opening located at the anterior tip of the head (photo); proboscis armed with a stylet (except in the leechlike genus Malacobdella)(Class Enopla) 23
2a Head without cephalic slits (Order Palaeonemertea and one species [Baseodiscus princeps] of the order Heteronemertea) 3
2b Head with cephalic slits (Order Heteronemertea) 10
3a With conspicuous nematocyst-like structures in the epidermis; length not exceeding 1 cm; interstitial Cephalothrix pacifica
3b Without nematocyst-like structures in the epidermis; length usually much greater than 1 cm; not interstitial 4
4a Body either with conspicuous white rings or longitudinal lines, or both 5
4b Body color more or less homogeneous, with neither rings nor longitudinal lines 7
5a General color deep red, interrupted by white rings that are spaced at intervals about equal to the width of the body; without longitudinal lines; anterior margin of head white Tubulanus albocinctus
5b General color brownish, interrupted by white rings; with white longitudinal lines; anterior margin of head not white 6
6a General color orange-brown to chocolate; with 5 or 6 longitudinal lines consisting of densely packed white dots (besides a mid-dorsal line, there are 2 lines on both the right and left sides of the body, and sometimes a faint mid-ventral line is present); white rings evenly spaced Tubulanus sexlineatus
6b General color dark brown throughout most of the body, although the posterior region is slightly lighter; with 3 white longitudinal lines (a continuous mid-dorsal line and 2 lateral lines that are broken into dashes anteriorly); white rings not evenly spaced (the anteriormost band of white pigment lies just behind the level of the mouth and forms a V on the ventral surface) Tubulanus capistratus
7a General color cream, not more than 50 cm 8
7b General color ochre, orange, or reddish; length commonly exceeding 1 m, and sometimes attaining 3 m 9
8a Generally 10-30 cm long and flattened posteriorly; head milky white; intestinal diverticula conspicuous (gravid females pinkish in the intestinal region; males that contain sperm are light orange in this part of the body) Carinoma mutabilis
8b Less than 3 cm long and very slender; head not milky white; intestinal diverticula not conspicuous (gravid females may have mid-dorsal and mid-ventral stripes between the cream-colored ovaries that are in the lateral portions of the body) Tubulanus pellucidus
9a Head without eyespots and without a pair of anteroventral grooves; color uniformly orange or reddish Tubulanus polymorphus
Renier, 1804
9b Head with numerous eyespots and with a pair of oblique grooves on the anteroventral surface (these grooves are inconspicuous); color deep ochre to brownish Baseodiscus princeps
10a Caudal cirrus absent; length of proboscis sheath variable (it may be much shorter than the body or nearly as long as the body) 14
10b Caudal cirrus present (it may be missing, however, if the posterior end has been damaged); proboscis sheath usually as long as the body 11
14a Body relatively soft and slender, not markedly flattened or otherwise adapted for swimming; length usually less than 50 cm 15
14b Body firm and markedly flattened posteriorly, adapted for swimming; length sometimes more than 50 cm 17
15a Body with distinct transverse rings of a contrasting color 16
15b Body color homogeneous (creamy tan to pale salmon) and lacking transverse rings of a contrasting color (tip of head white) Micrura alaskensis
16a Dorsal surface mostly dark brown or purple, but with regularly spaced, transverse white lines that divide the dark color into rectangles (ventral surface ivory white); dorsal surface of head with a conspicuous orange triangle. Micrura verrilli
16b General color deep chestnut or some shade of brown, interrupted by irregularly spaced white rings; anterior tip and sides of head with a white border (the body fragments readily) Micrura wilsoni
23a Body leechlike, with a muscular attachment disk at the posterior end; proboscis without a stylet; commensal in the mantle cavity of bivalve molluscs (Siliqua patula, Macoma nasuta, M. secta, and probably others) Malacobdella sp
23b Body not leechlike, and without a muscular attachment disk at the posterior end; proboscis with a stylet; not commensal in the mantle cavity of bivalve molluscs 24
24a Semi-terrestrial, generally found under rocks and driftwood at the edges of bays and saltmarshes, at a level reached only by the highest tides (dorsal surface grayish green or bluish green, with a poorly defined, darker longitudinal stripe; with 4 clusters of eyespots on the head, the anterior clusters with about 40 eyespots each, the posterior clusters with about 20 eyespots; length up to 25 cm) Pantinonemertes californiensis
24b Truly marine, not restricted to a level reached only by the highest tides 25
25a Stylet shaft with helical grooves and ridges 26
25b Stylet shaft smooth 29
26a With a conspicuous statocyst dorsal to each half of the brain; length usually less than 5 mm; interstitial Ototyphlonemertes americana
26b Statocysts absent; length much greater than 5 mm, not interstitial 27
27a Proboscis sheath less than 1/5 the length of the body; proximal portion of stylet discoidal and inconspicuous; length up to 1 m (fairly stout and conspicuously flattened; color typically tan, with light brown specks, or slightly purplish; dorsal surface darker than the ventral surface) Emplectonema purpuratum
27b Proboscis sheath more than 1/5 the length of the body; proximal piece of stylet prominent; length not often more than 30 cm 28
28a Dorsal surface brown to purple-brown, ventral surface creamy yellow; typically with 2 or 3 sacs of reserve stylets (an average of 4 stylets in each sac) Paranemertes peregrina
28b Color uniformly flesh to pale orange; typically with 4-6 sacs of reserve stylets (about 6 stylets in each sac) Paranemertes sanjuanensis

Taxonomic Levels Represented in This Key:

  Baseodiscus princeps
  Cerebratulus herculeus var latus (not in key)
  Micrura verrilli
  Paranemertes peregrina
  Tubulanus polymorphus

Not in Key but present on our coast:
  Amphiporus bimaculatus

Page created by Dave Cowles, 2004
Edited by:  Dave Cowles, 2005, 2012