|Some authors place the
Opisthobranchia and Pulmonata within the clade
Heterobranchia. So, we've decided to include an addendum containing the
marine pulmonates so all the marine heterobranchs will be covered
on the site. Pulmonata contains most land snails and slugs, most fresh
water snails and only a few marine species. All of them are
hermaphrodites and most can absorb oxygen from the air via a modified
mantle cavity. Three families traditionally placed in the Pulmonata are
from Hawaii: Onchidiidae (placed in the
Opisthobranchia in Kay, 1979), Ellobiidae (formerly Melampidae) and
Siphonariidae (placed in the Opisthobranchia in Grande, et. al., 2004
and Medina, et. al., 2011).
Kocot, et. al. (2011) recovers Opisthobranchia as paraphyletic with
respect to Pulmonata. That would suggest moving all the marine
pulmonates into the Opisthobranchia. However, they haven't been
traditionally considered opisthobranchs so we've decided to leave them
in an addendum, at least for now.
Bouchet, et. al., 2017 places the Sacoglossa and Pyramidellidae in with
the pulmonates. They also include the Acochlidimorpha, a group of
small, worm-like species traditionally placed with the opisthobranchs.
As a matter of convenience, we're following suite for the latter but
not the former.
The following information is derived primarily from reconciling Pilsbry
(1917-1921), Kay (1979), and Severns (2011) with each other and with
our own material. So, the IDs should be viewed as tentative, pending
further work. Unlike for the opisthobranchs, we haven't kept extensive
notes on these families--no running log of finds or detailed records of
the source of photographed animals. Therefore, we can't guarantee that
it includes the latest names and it may not be as comprehensive as the
|The Parheylidae are small,
worm-like animals in the order Acochlidimorpha (= Acochlidiacea; = Acochlidia). They lack shells and have short, paired tentacles on the head. Like most
Acochlidimorpha, they live interstitially in sand. There are at least
three species in Hawaii in the genera Microhedyle,
Paraganitus and Pontohedyle
Information on the family was primarily provided by
|The family Onchidiidae
includes slug-like mollusks that live in the high intertidal. They lack
a shell and have tuberculate mantles. They feed on micro-algae. One
species in the genus Peronia
is known from Hawaii.
|The family Ellobiidae
includes primitive pulmonates that live in the high intertidal and
supratidal zones. About 14 species are known from Hawaii including the
genera Allochroa, Auricularia, Blaunereia,
Laemodonta, Melampus and Pedipes.
|The family Siphonariidae
includes limpet-like species that inhabit the intertidal and subtidal.
At least three species are found in Hawaii in the genera Siphonaria and Williamia, the former intertidal
and the latter subtidal. They feed on micro-algae.
Medina, et. al., (2011) recovers the Siphonariidae as the sister group
to the Sacoglossa and they could be
inserted in the main list as an opisthobranch order under the name
Siphonariacea (or be grouped with the Sacoglossa as the Siphoglossa).
However, since they haven't been traditionally considered
opisthobranchs, we've decided to leave them in the marine pulmonate
addendum, at least for now.