Northern Rock Barnacle Classification Essay

TAXONOMY:

Kingdom – Animalia
Phylum – Arthropoda
Subphylum – Crustacea
Class – Maxillopoda
Subclass – Thecostraca
Infraclass – Cirripedia
Superorder – Thoracica
Suborder – Balanomorpha
Superfamily – Balanoidea
Family – Archaeobalanidae

DESCRIPTION:

Balanus balanoides, otherwise known as the northern rock barnacle or the acorn barnacle, is the only sessile crustacean. Barnacles will attach to almost any surface that is consistently submerged by brackish or saltwater. In their larval nauplius stage, barnacles swim around as zooplankton and feel around for a suitable spot with their adhesive antennae. The barnacle then secretes calcium carbonate, which grows to form the hard shells that constitute the familiar form of the barnacle. Four of the plates combine to form a door, which can be opened or closed by the muscles of the barnacle so that it can extend its long, feathery cirri to catch planktonic food particles. The gills of the barnacle are located on these cirri as well. Barnacles are hermaphrodites, but they still need to reproduce sexually with a neighbor. They accomplish this using a retractable tube of semen that can extend up to six inches to another barnacle. The barnacle has only one eye, which is primarily sensitive to light and dark. The hairs on the cirri are another source of sensory information.

ILLUSTRATION KEY:

BARNACLE 1

A – cirri

B – penis

C – anus

D – testicle

E – mantle

F – antennae

G – channels from cement glands

H – cement gland

I – ovary

J – mantle cavity

K – oviduct

L – eye

M – mouth

BARNACLE 2

A – non-movable plate

B – movable plate

C – attached base

REFERENCES:

“Barnacles.” Woods Hole Oceanographic Institution. Web. 16 Nov. 2015. <http://www.whoi.edu/science/B/people/kamaral/Barnacles.html>.

White, N. (n.d.). An acorn barnacle – semibalanus balanoides – general information. Retrieved November 17, 2015, from http://www.marlin.ac.uk/speciesfullreview.php?speciesID=4328

 

Balanus is a genus of barnacles in the familyBalanidae of the subphylum Crustacea.

This genus is known in the fossil record from the Jurassic to the Quaternary periods (age range: from 189.6 to 0.0 million years ago.). Fossil shells within this genus have been found all over the world.[1]

Description[edit]

The bodies of these organisms are totally enclosed by a stony gray-whitish shell. The size of these shells ranges from 5 millimeters to 10 centimeters. They take the form of a cone consisting of six plates fixed on the rocks. The active animal can only be observed within the water when the shell opens and the barnacles expose two branched appendages (cirri ) regularly hitting the water to catch food. They mainly feed on plankton.

Habitat[edit]

These barnacles can be found in coastal areas at low shallow depth, although they can also be seen living out of the water. They commonly colonize stones, rocks and shells. They are found in abundance on the shells of mussels.

Species[edit]

Species within the genus Balanus include:[2]

  • Balanus balanus(Linnaeus, 1758)
  • Balanus bloxhamensisWeisbord, 1966
  • Balanus borsodensisKolosváry, 1952
  • Balanus calidusPilsbry, 1916
  • Balanus campbelliFilhol, 1886
  • Balanus chisletianusSowerby, 1859
  • Balanus citerosumHenry, 1973
  • Balanus connelliCornwall, 1927
  • Balanus crenatusBruguiére, 1789
  • Balanus curvirostratusMenesini, 1968
  • Balanus darwiniiSeguenza, 1876
  • Balanus ecuadoricusPilsbry & Olson, 1951
  • Balanus flosculoidusKolosváry, 1941
  • Balanus gizellaeKolosváry, 1967
  • Balanus glandulaDarwin, 1854
  • Balanus hohmanniPhilippi, 1887
  • Balanus humilisConrad, 1846 (extinct)
  • Balanus imitatorZullo, 1984 (extinct)
  • Balanus irradiansZullo & Guruswami-Naidu, 1982
  • Balanus irregularisBroch, 1931
  • Balanus kanakoffiZullo, 1969
  • Balanus kondakoviTarasov & Zevina, 1957
  • Balanus laevisBruguiere, 1789
  • Balanus laguairensisWeisbord, 1966
  • Balanus leonensisWeisbord, 1966
  • Balanus microstomusPhilippi, 1887
  • Balanus minutusHoek, 1913
  • Balanus mirabilisKrüger, 1912
  • Balanus newburnensisWeisbord, 1966
  • Balanus nubilusDarwin, 1854
  • Balanus ochlockoneensisWeisbord, 1966
  • Balanus pannonicusKolosváry, 1952
  • Balanus parkeriZullo, 1967
  • Balanus perforatusBruguiére, 1789
  • Balanus poecilusDarwin, 1854
  • Balanus polyporusPilbry, 1924
  • Balanus provisoricusKolosváry, 1961
  • Balanus pulchellusRen, 1989
  • Balanus rhizophoraeRen & Liu, 1978
  • Balanus rostratusHoek, 1883
  • Balanus sauntonensisParfitt, 1871
  • Balanus similisWeltner, 1922
  • Balanus spongicolaBrown, 1844
  • Balanus subalbidusHenry, 1974
  • Balanus tamiamiensisRoss, 1964
  • Balanus trigonusDarwin, 1854
  • Balanus tuboperforatusKolosváry, 1962
  • Balanus tumoriferKolosváry, 1962
  • Balanus uliginosisHenry, 1973
  • Balanus vadasziKolosváry, 1949
  • Balanus veneticensisSeguenza, 1876
  • Balanus withersiPilsbry, 1930

The species Balanus balanoides (common barnacle, common rock barnacle, northern rock barnacle) has been reclassified as Semibalanus balanoides in the family Archaeobalanidae, due to its membranous base.

References[edit]

External links[edit]

Wikimedia Commons has media related to Balanus.
Fossil shells of Balanus from Pliocene

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