green, little purple
young, 1.8 mm
Lamprohaminoea cf. ovalis (Pease, 1868)
|Maximum size: 18 mm.
a strongly inflated transparent shell without spiral
striae. The animal is translucent green variably spotted with orange
and purple. The orange spots showing through the shell usually have
irregular white rings. Younger animals are often darker than mature ones
with proportionately larger spots. As the animals mature, they develop
fine rust-brown flecks first on the foot, then on the rest of the body.
Rarely, the purple spots may be lacking. It can be distinguished from Lamprohaminoea
cymbalum by the lack of broadly confluent orange spots showing
through the shell and, usually, by its more extensive purple spotting.
(Note 1) It can be distinguished from Lamprohaminoea
sp. #1 by its smaller orange spots.
Lamprohaminoea cf. ovalis is
a common nocturnal species found at highly protected to moderately
protected sites in rocky and mixed habitats as well as in Halimeda kanaloana beds. It
occurs at depths of < 1 to 12 m (< 3 to 39 ft). It is usually
associated with patches of the blue-green algae Lyngbya on which it
probably feeds. Copulating pairs are often found crawling together at
night with the head of the trailing animal overlapping the "tail" of
the other. (Note 2) It lays an elongate, white
to faintly greenish egg mass containing a "slinky-like" egg string and
attached by an adhesive surface. The egg masses usually acquire a
coating of sand or detritus in the field and hatch in about four days
in the laboratory.
Big Island, Maui, Oahu, Niihau and Midway: widely distributed in the western
Pacific; also in the eastern Pacific.
Taxonomic notes: This species is probably listed in Severns, 20ll as Haminoea sp. 2 cf. ovalis. It's also mentioned as Haminoea ovalis
in Kay, 1979. Given the high variability in this species, there's some
chance that DNA work will split it (or indicate hybridization with L. cymbalum?).
Photo: CP: 17
mm: Hekili Point, Maui; Nov. 16, 2002.
Observations and comments:
1: Pam Madden found many animals in an artificial tide pool on the Big Island. Among these were
large animals that had reduced purple spotting and a more opaque green
background color giving them a closer resemblance to L. cymbalum.
However, smaller animals showed intergrading in these traits and
animals of all sizes lacked broadly confluent orange spots. The animals
were also photographed in the open in late afternoon and had some algal
growth on their shells, atypical for L. cf. ovalis. Perhaps, unusual conditions in the pool (different temperature, different water flow, different food, lack of usual predators...) influenced both color characteristics and behavior? (see photos)
Note 2: Although not visible from the
top, the greatly elongated penis of the posterior animal is inserted
in the genital aperture of the first one while they are crawling. When
a pair was carefully collected on Sept. 30, 1997 they remained
"attached" for over 24 hours before separating.