Tubulanus albocinctus

Tubulanus albocinctus

Biological Flags

  • Ecosystem: Marine
Languages: English

Overview

Type Locality

Rather common in 50-100 fathoms between San Pedro and Catalina Island, California. The worms live among red algae, having almost exactly the same color, so that they are not easily discovered among the contents of the trawl. They are found associated with Taeniosoma punnetti and exhibit a similar tenacity of life.

Repository

Set of 9 histological slides deposited at the Peabody Museum of Natural History Yale University

General Description

Body stout and firm, less flattened than other Tubulanus speices. Head wider than body. Deep red color (sometimes cherry or brick red) with series of narrow white rings not thicker than a thread. There may be 50-100 rings along the entire length of the body. Tip of the snout has a narrow terminal border of white extending to the ventral surface. The general body color becomes lighter in the intestinal region which is lightly-yellowish. The ventral surface is lighter than the dorsal.

Description

External Appearance

Deep cherry or brick red, with series of very narrow (width of a thread) white rings but without longitudinal lines. Body firm, stout, 30 cm long with white rings at frequent intervals throughout the body. Tip of snout has a narrow, terminal border of white extending back along the lateral margins of the head and ventral surface. The first white ring is in the neck region and is interrupted by the mouth. The general body color becomes gradually lighter to a slightly yellowish tinge in the intestinal region. The ventral surface is a lighter color than the dorsal and appears greyish.

Body rather stout for genus, but can become much more elongated than the figures indicate; not much flattened, rather firm, less soft than Tubulanus frenatus. Head of moderate size, of variable shape, broader than neck, from which it is demarcated by an annular constriction. When body is strongly contracted, however, the anterior portions become much swollen and wrinkled, and the head withdrawn into the body until it is partially hidden from view from above. A pair of very shallow transverse grooves lie on the lateral margins of head, just in front of neck. Esophageal region rounded, intestinal region not much flattened, posterior extremity not slender.

Proboscis pore subterminal; proboscis rather small. Mouth situated just back of annular constriction marking the neck, of variable size according to state of contraction of body.

Body Wall

Fibrous crossings between the external and internal muscular layers of the body walls are poorly developed.

Digestive System

No particular differences from other species in this genus.

Blood Vascular System

Cephalic blood lacunae of large size. Their branches pass posteriorly as large lateral vessels or lacunae which send off unusually numerous branches around the esophagus. These esophageal lacunae pass ventrally well beneath the esophagus and exhibit abundant anastomoses as in some species of Cerebratulus. The rhynchocoel vessels originate some distance behind the mouth region, though not as far posteriorly as in Tubulanus cingulatus.

Proboscis and Rhynchocoel System

Rather large size for Tubulanus genus with muscular layers and pair of large nerves.

Excretory System

The excretory tubules are limited to about the third and fourth fifths of the esophageal region. Anteriorly there are several canals which branch profusely amoung the lateral and esophageal blood vessels. Farther back these branches unite into about five to eight longitudinal canals on each side, which lie above the lateral blood lacunae and dod note join until they are near the efferent ducts. Here they unite to form a rather large lacuna, as in Tubulanus cingulatus, from the dorsal wall of which the efferent duct leads to the dorso-lateral aspect of the body.

Nervous System

Brain and lateral nerves as in other species. Cephalic nerves numerous and of large size. Median dorsal nerve small.

Sensory Organs

Cerebral and lateral sensory organs are less well-developed than in other species described from the Pacific coast.

Glands

Cephalic glands are voluminous and occupy a great portion of the tissues of the head in front of the brain.

Size

up to 30cm in length and 4mm in width

Additional Information

Color after preservation in formalin or alcohol dull reddish brown or purplish, with very faint white rings, and with abrupt change in color at the second white ring, the parts anterior being brownish, while those immediately behind the ring are deep purple. White terminal cephalic border remains conspicuous when body is not strongly contracted.

Sundberg & Hylbom 1994 remark that there is insufficient description of anatomy in Coe (1940) and this species may be considered species inquirenda

Ecology

Habitat

Sublittoral, dredged among red algae at depths of 100-200 m.

Distribution

Pacific coast of USA (southern California)

Systematic Discussion

Pacific coast of USA (southern California)

References

Coe, W. R. (1904).  Nemerteans of the Pacific coast of North America. Part II. Harriman Alaska Series. 11, 111–220.
Gibson, R. (1995).  Nemertean species and genera of the world: an annotated check-list of original names and description citations, synonyms, current taxonomic status, habitats and recorded zoogeographic distribution. Journal of Natural History . 29, 271–562.