Haminoeoidea is a taxonomic superfamily

Taxonomic rank

In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...

 of small sea snail

Sea snail

Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....

s or bubble shells, marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 opisthobranch gastropod mollusks in the clade Cephalaspidea, the headshield slugs and bubble snails.

These cephalaspidea

Cephalaspidea

The suborder Cephalaspidea, also known as the headshield slugs and bubble snails, is a clade of sea slugs and bubble snails, marine gastropod mollusks within the larger clade Euopisthobranchia....

ns do have distinct anatomical

Anatomy

Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...

 and morphological

Morphology (biology)

In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....

 characteristics, but unfortunately many species were described only from empty shells

Gastropod shell

The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...

. For proper clarification of the taxonomy, those species still need the research necessary to provide a good description of the external and internal anatomy of the living animal.

Habitat

One can often find these bubble snails in enormous numbers, burrowing in mud on intertidal and sublittoral beds of green algae such as for example, the sea lettuce

Sea lettuce

The sea lettuces comprise the genus Ulva, a group of edible green algae that is widely distributed along the coasts of the world's oceans. The type species within the genus Ulva is Ulva lactuca Linnaeus, "lactuca" meaning lettuce...

, Ulva lactuca.

Shell description

These bubble snails have thin, inflated shells ranging in shape from ovoid to flat and oval. They have an involute (sunken) spire.

Description of live animal

The soft parts of the animals can retract completely or partially into their shells, and yet this offers them scant protection, because the aperture

Aperture (mollusc)

The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

 is rather wide and there is no operculum

Operculum (gastropod)

The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

. Furthermore, the shell is very fragile and can easily be crushed by a predator.

The cephalic shield of most species in this superfamily has two hind lobes that lie back on the front of the shell. The black eyes are usually buried just beneath the surface of the head.

Predators

Their predators include species of carnivorous aglajids

Aglajidae

Aglajidae is a family of often colorful, medium-sized, sea slugs, marine opisthobranch gastropod mollusks. These are not nudibranchs; instead they are headshield slugs, in the clade Cephalaspidea.-Genera:...

 such as Navanax inermis

Navanax inermis

Navanax inermis is a species of predatory sea slug, a marine opisthobranch gastropod mollusk in the family Aglajidae and the order Cephalaspidea, the headshield slugs and bubble snails....

.

Families, genera, species

Families, genera and species within the Haminoeoidea include:

• Superfamily Haminoeoidea
  • Family Haminoeidae
    Haminoeidae
    Haminoeidae, commonly known as the haminoeid bubble snail family, is a taxonomic family of sea snails, marine opisthobranch gastropod mollusks in the superfamily Haminoeoidea....
    
    
  • Family Bullactidae Thiele
    Johannes Thiele
    Johannes Thiele, full name Karl Hermann Johannes Thiele was a German zoologist specialized in malacology. His Handbuch der systematischen Weichtierkunde is a standard work...
    
    , 1926
    • Genus Bullacta Bergh, 1901
      • Bullacta exarata
        Bullacta exarata
        Bullacta exarata, common name the Korean mud snail, is a species of a sea snail or bubble snail, a marine gastropod mollusc in the family Haminoeidae, the bubble snails....
        
        Philippi, 1848 – Distribution: China, Yellow Sea, Indo-Pacific
  • Family Smaragdinellidae Thiele
    Johannes Thiele
    Johannes Thiele, full name Karl Hermann Johannes Thiele was a German zoologist specialized in malacology. His Handbuch der systematischen Weichtierkunde is a standard work...
    
    , 1925 – Oval yellow-green shell with sunken spire; very large aperture.
    • Genus Phanerophthalmus A. Adams, 1850
      • Phanerophthalmus cylindricus (Pease, 1861) – Distribution: Indo-Pacific, Hawaii
      • Phanerophthalmus smaragdinus Ruppell & Leuckart, 1828 – Distribution: tropical Indo-West Pacific, Hawaii – Length: 16 mm – Description: herbivore with a rather small cephalic shield; small enclosed mantle cavity ending in an exhalant siphon; small shell is partially enclosed in the mantle; color: brown to purple.
    • Genus Smaragdinella A. Adams & Reeve, 1848
      • Smaragdinella algirae Forbes, 1844
      • Smaragdinella calyculata Broderip & Sowerby 1829 – Distribution: Japan, Indo-Pacific – Length: 8 mm – Description: green mantle with dark green spots
      • Smaragdinella sieboldii A. Adams, 1864