following discussion deals with the conventions of labeling,
organization and methods that we follow throughout the site.
The purpose of this site is to present the observations of the authors
and other Hawaiian researchers who have contributed to it. Therefore,
we don't include comprehensive discussions of the species or,
necessarily, restate reports of their behavior/characteristics from
elsewhere in the Pacific. For that, we refer the reader to Bill
Rudman's Sea Slug Forum and other sites. Furthermore, conclusions and
interpretations on this site are based primarily on our own
observations and do not necessarily reflect the observations or
opinions of other researchers (unless otherwise noted).
Although we may suggest that some species might be synonyms, we do not
intend to make nomenclatural changes on this site. In cases where the
assignment of a genus is uncertain we place a "?" in parenthesis after
Nomenclature is based on the recommendations and preferences of Dr.
Terry Gosliner with the exception of a few instances where we have
to disagree" on matters of splitting or lumping. Final choices (and
any errors) in such cases are our responsibility.
The purpose of the thumbnail section is to provide a "cascading
gallery" for quick identification. The introductory material
for each taxon has been deliberately kept to a minimum so readers won't
have to scroll down too far to get to the thumbnails. For further
discussion, we direct the readers to other sites that deal with such
subjects in greater detail. All thumbnails are smaller versions of
photos appearing elsewhere on the site and photographers are credited
under the primary photos. Each taxon is also linked to a comprehensive
species list for those who wish to go directly to the descriptions.
Finally, we provide a single page containing all the thumbnails without
introductory material for those who find that format convenient.
In those few cases where we do not have a photo taken in Hawaii of a
species that, nevertheless, is known to be present we may include a
taken elsewhere as an aid to identification. These photos are
identified by the abbreviation "(PNH)" after the name bellow the
thumbnail and by the phrase "(Photo not from Hawaii)" below the photo
on the species page. If a species is mentioned in the family
introduction as "possibly Hawaiian but not confirmed" a link is
provided to photos of the species on another site.
When we've changed the genus of unidentified or undescribed species
that are listed by number, the numbers usually haven't been altered
(except to resolve conflicts) in order to minimize relabeling. So, they
may not reflect the number of species in their present genus. For
example, use of "Cuthona sp.
#17" doesn't necessarily mean that there
are 17 unidentified Cuthona
spp. on the current list.
Many animals were photographed on an artificial sand background.
Therefore, such photos should not be interpreted as implying that
they are sand-dwellers. Artificial rock backgrounds were also used for many "dish" shots.
Our intent is to portray the animals, themselves, in a manner that is as close to
reality as possible. In many cases, we've used Photoshop to mitigate
"photographer errors" (poor exposure, poor white balance, confusing
back-scatter, etc.). But, the purpose of such editing has always
been to restore the image, as closely as possible, to the original appearance of the animal, not to alter it.
The maximum size is the greatest body length of Hawaiian animals that
are aware of either from our own observations or the literature (we do
not routinely include data from elsewhere in the Pacific although major
differences may be noted for some species). If the length is from the
literature or another researcher the source is stated in parenthesis.
In some cases, the body length of shelled species is estimated from
shells by comparison with photos of other specimens. In species where
only shells are known, the shell length is given. In all cases, the
maximum size should be viewed with caution for relatively rare species
due to the small sample size.
The identification section provides a brief description of the species
with emphasis on those characteristics that we believe are most useful
in distinguishing it from similar-appearing species. It also discusses
The natural history section provides a brief discussion of
distribution, habitat, diet, behavior and reproduction. All statements
are based on the observations of the authors unless otherwise noted.
How common a species appears to be is influenced by the pattern of
sampling, sampling techniques, etc. It may also vary with
habitat and season. In addition, there is often a substantial
difference between the numbers seen by divers and the actual numbers
indicated by random sampling. For these reasons, it is difficult to
establish a fixed definition for the terms used. Nevertheless, we will
try to apply the following generalities: rare--found less than 5
times by the authors, moderately rare--found 5 to 20 times by the
authors; moderately common--found 20 to 100 times by the authors,
common--found over 100 times by the authors. When used in conjunction
with a designated habitat, the terms represent a rough extrapolation
from smaller samples. In some cases, we may use such phrases as "common
but rarely seen" with
regard to species that are frequently found in quantitative sampling
but seldom seen in the field due to their small size, cryptic
coloration or retiring habits.
Exposure deals with the amount of wave action or surge in shallow water
at particular sites and is somewhat subjective due to the complexity of
those sites. However, the following examples provide a rough bench mark
for our usage: highly protected (Kaneohe Bay, Kahului harbor),
protected (back-reef at Hekili Point, Kapalua Bay), moderately
protected (Napili Bay, Honolua Bay), moderately exposed (Maliko Bay,
reef crest at Hekili Point), exposed (Papawai Point, Black Rock,
Maalaea Bay) and highly exposed (Alelele Stream, Nakalele Point). When
animals extend to depths below the surge zone this convention may not
Descriptions of behavior and egg masses are based on a limited number
of anecdotal observations and should be regarded as tentative.
Most hatching times referred to as "in the laboratory" are based on egg
masses held in small, shaded, covered dishes with water changed about
twice a day. So, the average temperature probably approximated the mean
surface water/air temperature at the time of observation at Camp
Pecusa/Olowalu (with variation roughly tracking shaded air temperature
"near the beach").
The distribution section lists the islands in Hawaii where, to our
knowledge, the species has been found. It also lists where it is found
outside Hawaii. Since sample sizes are often low and coverage
incomplete, it should not be viewed as in any way comprehensive.
The taxonomic notes section offers a brief discussion of major issues
affecting nomenclature, as well as major synonyms and name changes
relative to well known Hawaiian guides. Links to Bill Rudman's Sea Slug
Forum or other sites are routinely provided for further discussion.
Also, the first Hawaiian sighting that we know of (based on specimens
photos) is credited even if a later date has been
published as the first Hawaiian record in the
The photo section lists the photographer for the photo at the top of
the page and relevant data regarding the photographed animal (when
known). The finder of the animal is credited if different from the
photographer. When the photographer or finder is one of the authors,
initials are used. If no finder is indicated the photographer is the finder.
The observations and comments section provides details of anecdotal
observations that support or expand upon statements made in the
remainder of the page. Internal links to the notes are provided for the
of the reader.
The additional photos section to the left includes thumbnails linked to
more photos of the species. They may provide other views or
close-ups useful for identification, illustrate intraspecific
variation, illustrate changes related to ontogeny (and other factors),
document behavior or illustrate egg masses. Further photos that
illustrate growth sequences, details, egg development, etc. may appear
on the linked pages without appearing as thumbnails in the side bar.
The gallery link at the
bottom of the section, if present, leads to additional photos, usually
the authors, that are presented at a reduced size as a further aid to