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Additional Photos
underside
sensory bristles
pale
young, mottled
young, lined, 4 mm
young, spotted
intermediate
without orange spots
shell
egg mass
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GALLERY
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Biuve cf. fulvipunctata (Baba, 1938)
Maximum size: 12 mm (excluding
"tail").
Identification:
This
cryptic
species is usually brown mottled in cream with orange
highlights. Most animals have a "W-shaped" cream mark on the head,
a cream patch on the posterior tip of the head shield and five orange
spots on the front of the head. However, young animals vary
considerably in color with some having uniformly distributed orange
spots or blue lines reminiscent of Chelidonura hirundinina. The latter still show the five orange spots on
the
front of the head and the cream posterior tip on the head shield
characteristic of Biuve cf. fulvipunctata.
They
also
have an orange line in the
center of the notum in contrast to the blue line in C. hirundinina. The white "W" may
be interrupted medially in young animals and the length of the "tail"
is variable.
Natural history:
Biuve cf. fulvipunctata
is a common nocturnal species found in protected to highly exposed
locations. It occurs in rocky habitats at depths of
1-6 m (3-20 ft) and (occasionally) in Halimeda
kanaloana beds at up to 12 m (40 ft). It probably feeds on small
acoelomate flatworms and has been observed "striking" (though
ultimately rejecting) Convolutriloba longifissura (Note 1) Kay (1979) states that it can be found among the stipes of Boodlea and Jania during the day. A fringe of sensory hairs at the
front of the head is used to detect prey. In dishes, its egg masses
are small, irregular white clumps composed of an irregular string.
However, it is likely that they remain sack-like when laid in the field
where their sticky surfaces can collect detritus for reinforcement.
Hatching occurs in about four days in the laboratory.
Distribution:
Big Island, Maui, Oahu, Kauai and French Frigate Shoals.
Taxonomic notes:
This
is
the species listed as Chelidonura
amoea Bergh, 1905 in Kay, 1979. It was first recorded in Hawaii
from Kaneohe Bay, Oahu by Terry Gosliner in May, 1973. The Hawaiian
population is probably different from the wide-spread Indo-Pacific form
formerly included with it under the name Chelidonura fulvipunctata. (Zamora-Silva & Malaquias, 2017) The animals with relatively large orange spots extending onto the foot (see photo)
are more common in the Western Pacific and show some sign of
intergrading with mottled forms in that region. So, there's a chance
that they might represent the Indo-Pacific form. Some sources use Aglaja fulvipunctata for that species.
Photo: CP:
4.6 mm: Hekili Point, Maui; March 30, 2006.
Observations and comments:
Note
1: Several times in 1998 6-8 mm
animals were placed in dishes with 1.5-2 mm specimens of Convolutriloba longifissura (tentatively listed by Poulter as Convoluta sp. in section two of
Reef and Shore Fauna of Hawaii, 1987). On contact with their sensory
hairs, the worms were "inhaled" with a speed comparable to the feeding
strike of a scorpion fish, e. g., much too fast to make out any details
of the movement. Whether the worm is "on the menu" normally is still
open to question, however, since (in all cases) its crushed remains
were regurgitated about 15-20 seconds after it was taken. It may be
close enough to their normal prey to trigger their feeding reflex but
proves unpalatable after ingestion (perhaps, due to a defensive
chemical?). When offered a second species of 2 mm worm on a later
occasion, they showed no response.
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