11.1.3 Heterobranchia

Overview

Name origins: “Hetero-,” different; “branchia,” gills. Thus, heterobranchs are “differently gilled” gastropods.

Among other synapomorphies, Heterobranchia all share in common a “sinistral larval shell produced by a planktotrophic veliger” (Ponder and Lindberg, 1997, p. 229). This clade of Gastropoda is diverse and, like the Caenogastropoda, is ecologically successful as well, occupying marine, freshwater, and terrestrial habitats (Jörger et al., 2010). The phylogenetic study of Zapata et al. (2014) showed Heterobranchia as the sister group of Caenogastropoda (see here).

Most heterobranchs belong in a subgroup called the Euthyneura.  Traditional groupings within the Euthyneura include Pulmonata (many land snails and slugs) and Opisthobranchia (sea slugs such as nudibranchs and bubble snails). The phylogenetic study of Jörgen et al. (2010), however, demonstrated that these traditional groups are not monophyletic. Our modern understanding of heterobranch relationships includes the following major groups:

  • “Lower Heterobranchia:” a paraphyletic assortment of predominantly marine gastropods that are phylogenetically basal relative to the monophyletic clade Euthyneura. Example: the sundial shells, Architectonica.
  • Euthyneura: a monophyletic clade that, according to Jörgen et al. (2010) includes three subclades:
    • Nudipleura: the marine nudibranchs, one group of sea slugs. Species often exhibit dazzling colors and fascinating defenses, including the ability to steal and co-opt the stinging cells (nematocysts) of some cnidarians. They lack shells as adults.
    • Euopisthobranchia: another group of marine sea slugs, many of which have shells. Some examples include sea hares, headshield slugs, bubble snails, and pteropods.
    • Panpulmonata: this clade contains mostly air-breathing, terrestrial gastropods, including common garden snails and slugs. Panpulmonata also includes two clades of air-breathing “false limpets,” Siphonarioidea and Trimusculoidea.

A molecular clock study by Zapata et al. (2014) suggests that the Heterobranchia clade originated sometime in the Carboniferous (Mississippian and Pennsylvanian periods).

Gallery of Heterobranchia
  • “Lower Heterobranchia:” Modern specimen of Architectonica maxima from Tosa, Japan (PRI 55220).

  • Nudipleura: A nudibranch, photographed at an aquarium.

  • Euopisthobrachia: Internal shell of the modern sea hare Dolabella (PRI 70097).

     

  • Euopisthobranchia: Modern Bullaria gouldiana from Orange County, California (PRI 70098).

  • Siphonariidae: Siphonaria gigas from Panama (PRI 70100).

Examples of Heterobranchia:
The Blue Dragon

The blue dragon, Glaucus atlanticus, is a brightly colored, swimming marine nudibranch (Nudipleura clade). A 2010 viral video characterized this species as a “real life Pokemon.” This heterobranch protects itself by stealing and co-opting stinging cells from the Portuguese man-of-war; many nudibranchs similarly steal the weaponry of cnidarians for their own defense.


Bubble Snail

Bubble snails are euopisthobranchs. As they crawl on the seafloor, their shells cover just a fraction of their bodies. The video below shows a kind of Indonesian bubble snail called a Miniature Melo (Micromelo undatus).

Headshield Slug

Species belonging to the marine headshield sea slug genus Navanax are predatory members of the Euopisthobranchia clade. The short video below shows a Navanax eating a bubble snail, another kind of euopisthobranch.

Sea Butterflies and Sea Angels

PTEROPOD IMAGE HERE

Sea butterflies and sea angles are pteropods (“wing-foot;” the “p” is silent), both shown in the video below. These small euopisthobranchs spend their lives in the water column (i.e., they are pelagic). The fine calcium carbonate shells of these animals–which easily dissolve in acidic water–have proven to be important indicators that the oceans are becoming more and more acidic due to the presence of higher amounts of dissolved carbon dioxide (see overviews by the Smithsonian and Los Angeles Times).

Escargot

HELIX IMAGE HERE

The edible terrestrial snails used for escargot belong to the species Helix pomatia (or, “burgundy snails”), which are panpulmonates. The life habits of similar snails are shown in a scene from the remarkable movie Microcosmos.

Banana Slug

Banana slugs (genus Ariolimax), along with other terrestrial slugs, are panpulmonates. These slimy, brightly colored slugs occupy the redwood forests of California.

Families of Heterobranchia

Gofas (2016) recognizes the following gastropod families as members of the Heterobranchia († indicates extinct families). This list was copied from MolluscaBase on February 3, 2017 and is reposted here in concordance with the source material’s Creative Commons BY 4.0 license. The link associated with each name will direct you to additional information about that family on MolluscaBase.

SUBCLASS OPISTHOBRANCHIA

Order Acochlidiacea

Family Acochlidiidae Küthe, 1935
Family Aitengidae Swennen & Buatip, 2009
Family Bathyhedylidae Neusser, Jörger, Lodde-Bensch, Strong & Schrödl, 2016
Family Hedylopsidae Odhner, 1952
Family Pseudunelidae Rankin, 1979
Family Tantulidae Rankin, 1979
Family Asperspinidae Rankin, 1979
Family Parhedylidae Thiele, 1931

Order Anaspidea

Family Akeridae Mazzarelli, 1891
Family Aplysiidae Lamarck, 1809

Order Cephalaspidea

Family Acteocinidae Dall, 1913
Family Bullidae Gray, 1827
Family Retusidae Thiele, 1925
Family Rhizoridae Dell, 1952
Family Colinatydidae Oskars, Bouchet & Malaquias, 2015
Family Cylichnidae H. Adams & A. Adams, 1854
Family Diaphanidae Odhner, 1914 (1857)
Family Eoscaphandridae Chaban & Kijashko, 2016
Family Mnestiidae Oskars, Bouchet & Malaquias, 2015
Family Haminoeidae Pilsbry, 1895
Family Aglajidae Pilsbry, 1895 (1847)
Family Alacuppidae Oskars, Bouchet & Malaquias, 2015
Family Colpodaspididae Oskars, Bouchet & Malaquias, 2015
Family Gastropteridae Swainson, 1840
Family Laonidae Pruvot-Fol, 1954
Family Philinidae Gray, 1850 (1815)
Family Philinoglossidae Hertling, 1932
Family Philinorbidae Oskars, Bouchet & Malaquias, 2015
Family Scaphandridae G.O. Sars, 1878

Order Gymnosomata

Family Clionidae Rafinesque, 1815
Family Cliopsidae O. G. Costa, 1873
Family Notobranchaeidae Pelseneer, 1886
Family Pneumodermatidae Latreille, 1825
Family Hydromylidae Pruvot-Fol, 1942 (1862)
Family Laginiopsidae Pruvot-Fol, 1922

Order Nudibranchia

Family Aeolidiidae Gray, 1827
Family Facelinidae Bergh, 1889
Family Glaucidae Gray, 1827
Family Piseinotecidae Edmunds, 1970
Family Pleurolidiidae Burn, 1966
Family Unidentiidae Millen & Hermosillo, 2012
Family Fionidae Gray, 1857
Family Pseudovermidae Thiele, 1931
Family Flabellinidae Bergh, 1889
Family Notaeolidiidae Eliot, 1910
Family Aranucidae Odhner, 1936
Family Bornellidae Bergh, 1874
Family Dendronotidae Allman, 1845
Family Hancockiidae MacFarland, 1923
Family Lomanotidae Bergh, 1890
Family Phylliroidae Menke, 1830
Family Scyllaeidae Alder & Hancock, 1855
Family Tethydidae Rafinesque, 1815
Family Tritoniidae Lamarck, 1809
Family Arminidae Iredale & O’Donoghue, 1923 (1841)
Family Doridomorphidae Er. Marcus & Ev. Marcus, 1960 (1908)
Family Actinocyclidae O’Donoghue, 1929
Family Cadlinidae Bergh, 1891
Family Chromodorididae Bergh, 1891
Family Discodorididae Bergh, 1891
Family Dorididae Rafinesque, 1815
Family Akiodorididae Millen & Martynov, 2005
Family Calycidorididae Roginskaya, 1972
Family Corambidae Bergh, 1871
Family Goniodorididae H. Adams & A. Adams, 1854
Family Onchidorididae Gray, 1827
Family Dendrodorididae O’Donoghue, 1924 (1864)
Family Mandeliidae Valdés & Gosliner, 1999
Family Phyllidiidae Rafinesque, 1814
Family Aegiridae P. Fischer, 1883
Family Gymnodorididae Odhner, 1941
Family Hexabranchidae Bergh, 1891
Family Okadaiidae Baba, 1930
Family Polyceridae Alder & Hancock, 1845
Family Bathydorididae Bergh, 1891

Order Pleurobranchomorpha

Family Pleurobranchaeidae Pilsbry, 1896
Family Pleurobranchidae Gray, 1827
Family Quijotidae Ortea, Moro & Bacallado, 2016

Order Runcinacea

Family Ilbiidae Burn, 1963
Family Runcinidae H. Adams & A. Adams, 1854

Order Sacoglossa

Family Cylindrobullidae Thiele, 1931
Family Juliidae E. A. Smith, 1885
Family Oxynoidae Stoliczka, 1868 (1847)
Family Volvatellidae Pilsbry, 1895
Family Caliphyllidae Tiberi, 1881
Family Costasiellidae K. B. Clarke, 1984
Family Hermaeidae H. Adams & A. Adams, 1854
Family Limapontiidae Gray, 1847
Family Boselliidae Ev. Marcus, 1982
Family Jenseneriidae Ortea & Moro, 2015
Family Plakobranchidae Gray, 1840
Family Platyhedylidae Salvini-Plawen, 1973

Order Thecosomata

Family Cavoliniidae Gray, 1850 (1815)
Family Cliidae Jeffreys, 1869
Family Creseidae Rampal, 1973
Family Cuvierinidae van der Spoel, 1967
Family Sphaerocinidae A. W. Janssen & Maxwell, 1995 †
Family Limacinidae Gray, 1840
Family Cymbuliidae Gray, 1840
Family Desmopteridae Chun, 1889
Family Peraclidae Tesch, 1913

Order Umbraculida

Family Tylodinidae Gray, 1847
Family Umbraculidae Dall, 1889 (1827)

SUBCLASS PULMONATA

Order Hygrophila

Family Acroloxidae Thiele, 1931
Family Chilinidae Dall, 1870
Family Latiidae Hutton, 1882
Family Lymnaeidae Rafinesque, 1815
Family Physidae Fitzinger, 1833
Family Clivunellidae Kochansky-Devidé & Slišković, 1972 †
Family Planorbidae Rafinesque, 1815

Order Stylommatophora

Family Athoracophoridae P. Fischer, 1883 (1860)
Family Succineidae Beck, 1837
Family Achatinellidae Gulick, 1873
Family Azecidae Watson, 1920
Family Cochlicopidae Pilsbry, 1900 (1879)
Family Cerastidae Wenz, 1923
Family Draparnaudiidae Solem, 1962
Family Enidae Woodward, 1903 (1880)
Family Partulidae Pilsbry, 1900
Family Argnidae Hudec, 1965
Family Chondrinidae Steenberg, 1925
Family Gastrocoptidae Pilsbry, 1918
Family Lauriidae Steenberg, 1925
Family Orculidae Pilsbry, 1918
Family Pleurodiscidae Wenz, 1923
Family Pupillidae Turton, 1831
Family Pyramidulidae Kennard & B. B. Woodward, 1914
Family Spelaeoconchidae A. J. Wagner, 1928
Family Spelaeodiscidae Steenberg, 1925
Family Strobilopsidae Wenz, 1915
Family Valloniidae Morse, 1864
Family Vertiginidae Fitzinger, 1833
Family Acavidae Pilsbry, 1895
Family Dorcasiidae Connolly, 1915
Family Macrocyclidae Thiele, 1926
Family Strophocheilidae Pilsbry, 1902
Family Anadenidae Pilsbry, 1948
Family Ariolimacidae Pilsbry & Vanatta, 1898
Family Arionidae Gray, 1840
Family Binneyidae Cockerell, 1891
Family Oopeltidae Cockerell, 1891
Family Philomycidae Gray, 1847
Family Clausiliidae Gray, 1855
Family Filholiidae Wenz, 1923 †
Family Palaeostoidae H. Nordsieck, 1986 †
Family Dyakiidae Gude & B. B. Woodward, 1921
Family Archaeozonitidae Pfeffer, 1930
Family Euconulidae H. B. Baker, 1928
Family Gastrodontidae Tryon, 1866
Family Oxychilidae Hesse, 1927 (1879)
Family Pristilomatidae Cockerell, 1891
Family Trochomorphidae Möllendorff, 1890
Family Ariophantidae Godwin-Austen, 1888
Family Helicarionidae Bourguignat, 1877
Family Urocyclidae Simroth, 1889
Family Camaenidae Pilsbry, 1895
Family Cochlicellidae Schileyko, 1972
Family Elonidae Gittenberger, 1977
Family Helicidae Rafinesque, 1815
Family Helicodontidae Kobelt, 1904
Family Hygromiidae Tryon, 1866
Family Pleurodontidae Ihering, 1912
Family Sphincterochilidae Zilch, 1960 (1910)
Family Agriolimacidae H. Wagner, 1935
Family Boettgerillidae Wiktor & I. M. Likharev, 1979
Family Limacidae Batsch, 1789
Family Vitrinidae Fitzinger, 1833
Family Amphibulimidae P. Fischer, 1873
Family Bothriembryontidae Iredale, 1937
Family Bulimulidae Tryon, 1867
Family Cerionidae Pilsbry, 1901
Family Grangerellidae Russell, 1931 †
Family Megaspiridae Pilsbry, 1904
Family Odontostomidae Pilsbry & Vanatta, 1898
Family Orthalicidae Albers, 1860
Family Simpulopsidae Schileyko, 1999
Family Milacidae Ellis, 1926
Family Parmacellidae P. Fischer, 1856 (1855)
Family Trigonochlamydidae Hesse, 1882
Family Corillidae Pilsbry, 1905
Family Plectopylidae Möllendorff, 1898
Family Sculptariidae Degner, 1923
Family Charopidae Hutton, 1884
Family Cystopeltidae Cockerell, 1891
Family Discidae Thiele, 1931 (1866)
Family Endodontidae Pilsbry, 1895
Family Helicodiscidae H. B. Baker, 1927
Family Oreohelicidae Pilsbry, 1939
Family Thyrophorellidae Girard, 1895
Family Sagdidae Pilsbry, 1895
Family Diapheridae Panha & Naggs, 2010
Family Streptaxidae Gray, 1860
Family Urocoptidae Pilsbry, 1898 (1868)
Family Zonitidae Mörch, 1864
Family Vidaliellidae H. Nordsieck, 1986

Order Systellommatophora

Family Onchidiidae Rafinesque, 1815
Family Rathouisiidae Heude, 1885
Family Veronicellidae Gray, 1840

Families of Pulmonata Unassigned to Order

Family Bradybaenidae Pilsbry, 1934
Family Caryodidae Connolly, 1915
Family Cionellidae
Family Punctidae Morse, 1864
Family Rhytididae Pilsbry, 1893
Family Scolodontidae H. B. Baker, 1925
Family Oleacinidae H. Adams & A. Adams, 1855
Family Spiraxidae H.B. Baker, 1939
Family Testacellidae Cuvier, 1800
Family Amphibolidae Gray, 1840
Family Maningrididae Golding, Ponder & Byrne, 2007
Family Ellobiidae L. Pfeiffer, 1854 (1822)
Family Glacidorbidae Ponder, 1986
Family Acroreiidae Cossmann, 1893 †
Family Siphonariidae Gray, 1827

Unassigned Families of Heterobranchia

Family Cimidae Warén, 1993
Family Dolomitellidae Bandel, 1994 †
Family Heterosubulitidae Bandel, 2002 †
Family Kuskokwimiidae Frýda & Blodgett, 2001 †
Family Misurinellidae Bandel, 1994 †
Family Orbitestellidae Iredale, 1917
Family Tjaernoeiidae Warén, 1991
Family Trachoecidae Bandel, 1994 †
Family Acteonellidae Gill, 1871 †
Family Acteonidae d’Orbigny, 1843
Family Aplustridae Gray, 1847
Family Bullinidae Gray, 1850
Family Cylindrobullinidae Wenz, 1938 †
Family Tubiferidae Cossmann, 1895 †
Family Zardinellidae Bandel, 1994 †
Family Amphitomariidae Bandel, 1994 †
Family Architectonicidae Gray, 1850
Family Cassianaxidae Bandel, 1996 †
Family Ampezzanildidae Bandel, 1994 †
Family Anoptychiidae Bandel, 1994 †
Family Gordenellidae Gründel, 2000 †
Family Mathildidae Dall, 1889
Family Tofanellidae Bandel, 1995
Family Murchisonellidae Casey, 1904
Family Rhodopidae Ihering, 1876
Family Ceritellidae Wenz, 1938 †
Family Nerineidae Zittel, 1873 †
Family Nerinellidae Pchelintsev, 1960 †
Family Omalogyridae G.O. Sars, 1878
Family Stuoraxidae Bandel, 1994 †
Family Amathinidae Ponder, 1987
Family Heteroneritidae Gründel, 1998 †
Family Pyramidellidae Gray, 1840
Family Ringiculidae Philippi, 1853
Family Rissoellidae Gray, 1850
Family Cassianebalidae Bandel, 1996 †
Family Streptacididae Knight, 1931 †
Family Cornirostridae Ponder, 1990
Family Hyalogyrinidae Warén & Bouchet, 1993
Family Provalvatidae Bandel, 1991 †
Family Valvatidae Gray, 1840
Family Xylodisculidae Warén, 1992

References

Jörger, K. M., I. Stöger, Y. Kano, H. Fukuda, T. Knebelsberger, and M. Schröl. 2010. On the origin of Acochlidia and other enigmatic euthyneuran gastropods, with implications for the systematics of Heterobranchia. BMC Evolutionary Biology, 10: 323. DOI: 10.1186/1471-2148-10-323. Link.

Gofas, S. 2016. Heterobranchia. Accessed on February 3, 2017 through: MolluscaBase at http://www.molluscabase.org/aphia.php?p=taxdetails&id=14712.

Ponder, W. F. and D. R. Lindberg. 1997. Towards a phylogeny of gastropod molluscs: an analysis using morphological characters. Zoological Journal of the Linnean Society, 119: 83-265. DOI: 10.1111/j.1096-3642.1997.tb00137.x. Link.

Zapata, F., N. G. Wilson, M. Howison, S. C. S. Andrade, K. M. Jörger, M. Schrödl, F. E. Goetz, G. Giribet, and C. W. Dunn. 2014. Phylogenomic analyses of deep gastropod relationships reject Orthogastropoda. Prooceeding of the Royal Society, B, 281: 20141739. DOI: http://dx.doi.org/10.1098/rspb.2014.1739. Link.