ORDER
Cavibelonia
FAMILY
Simrothiellidae
TAXONOMY
Spiomenia spiculata Arnofsky, 2000, West European Basin, 55°7.7 min N, 12°52.5 min W, at a depth of 9,505 ft (2,897 m).
OTHER COMMON NAMES
None known.
PHYSICAL CHARACTERISTICS
Spiomenia spiculata has a curved body that tapers slightly toward the posterior end; it is usually widest at its midsection. It has a dorsofrontal sensory pit, dorsoterminal sense organ, and a mantle cavity opening partly closed off by spicules. The longest epidermal spicules on S. spiculata are found toward the rear of the organism near the opening to the mantle cavity. There are nine different types of spicules, including two types of copulatory spicules that occur in paired groups protruding through the mantle cavity. Several accessory copulatory spicules are grouped near the opening to the mantle cavity. The pedal groove contains three types of solid spicules. The radula of S. spiculata makes a single turn into paired anteroventral radular pockets; there are 22–25 teeth with 22–23 denticles per tooth. In addition, this aplacophoran has unusually large paired salivary glands on its upper surface that empty into the esophagus where it joins the radular sac.
DISTRIBUTION
West European Basin at a depth of 6,560–13,120 ft (2,000–4,000 m).
HABITAT
Nothing is known.
BEHAVIOR
Nothing is known.
FEEDING ECOLOGY AND DIET
Spiomenia spiculata does not appear to depend on cnidarians as a food source. It feeds on diatoms and unidentified spicules that resemble those found in sponges.
REPRODUCTIVE BIOLOGY
Members of this species are hermaphrodites.
CONSERVATION STATUS
Not listed by the IUCN.
SIGNIFICANCE TO HUMANS
Spiomenia spiculata is used in scientific research.
