Amphibalanus+amphitrite


 * Purple Acorn Barnacle (//Balanus amphitrite//)**

NAME

 * Binomial**: //Balanus amphitrite// Darwin 1854 (= //Amphibalanus amphitrite// Pitombo 2004)
 * Vernacular**: striped barnacle, the purple acorn barnacle and Amphitrite's rock barnacle

ETYMOLOGY
**//Balanus amphitrite// Darwin 1854** Balanus, being the name of the genus refers to chestnut or acorn in Latin. Da Costa (1778) named the unknown-then-shelled animals as [|Acorn shells] since they have comparable morphology to an acorn or a chestnut: they have hardened exterior shell (shell or wall plates for barnacles. Amphitrite is known to the goddess of the oceans and the wife of King Poseidon in Greek Mythology. There is no written explanation to the naming of ‘amphitrite’ to the barnacle, probably named it as such of its physical abilities to withstand desiccation when not submerged under seawater and permanently attach to a hard substratum on the coastline. //Balanus amphitrite// are hermaphrodites as opposed to its feminine background name.

**//Amphibalanus amphitrite// Pitombo 2004** ‘Amphibalanus’ is a combination of the words //amphitrite// and //balanus//. Genus Amphibalanus derived from phylogenetic revision of which a new subfamily //Amphibalaninae// was proposed and derived from original subfamily //Balaninae// (Pitombo, 2004). Pitombo (2004) evaluated evolutionary relationships amongst the subfamilies within family //Balanoidea// hence proposed a fourth subfamily the Amphibalaninae as being a monophylectic group, //Amphibalanus// gen. nov. and its allies based on new diagnostic morphological characters. Therefore, Balanus amphithrite automatically reverted into //Amphibalanus amphithrite// from this revision.

** Curent Status of Scientific Name **  Currently, the debacle of nomenclature i.e. usage of //Barnacle amphitrite// or //Amphibalanus amphithrite// still exist (Clare & Hoeg, 2008; Carlton & Newman, 2010). Clare and Hoeg (2008) supported retention of //B. amphitrite// due to “scarce” referencing of //A. amphitrite,// and outright critism of Pitombo (2004)’s methology of phylogenetic revision. They have suggested adaptation of a compromise nomenclature i.e. Balanus amphitrite (=Amphibalanus amphitrite) or vice-versa for the species. Carlton & Newman (2010), on the other hand refuted such claims stating that names changes, especially to non-systematists is often slow and does not reflect rejection from the scientific community and supports Pitombo’s revision.

** Vernacular Etymology ** In terms of vernacular names, it was named ‘striped barnacle’ because its wall plates have longitidunal coloured striations, however this term also encompasses other barnacle species e.g. Balanus cirratus. Also termed “Purple acorn barnacle” due to colour of the striations i.e. purple on its plates.



**TAXONAVIGATION**

Kingdom [|Animalia] -- Animal, animals, animaux Phylum [|Arthropoda] -- arthropodes, arthropods, Artrópode Subphylum[| Crustacea] Brünnich, 1772 – crustace, crustáceo, crustacés Class [|Maxillopoda] Dahl, 1956 Subclass[| Thecostraca] Gruvel, 1905 Infraclass[| Cirripedia] Burmeister, 1834 -- barnacles, bernacles <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Superorder[| Thoracica] Darwin, 1854 -- barnacles <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Order[|Sessilia] Lamarck, 1818 -- sessile barnacles <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Suborder [|Balanomorpha] Pilsbry, 1916 -- acorn barnacles <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Superfamily [|Balanoidea] Leach, 1817 <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Family [|Balanidae] Leach, 1817/ Amphibalanidae Pitombo, 2004) <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Genus [|Balanus] Da Costa, 1778 /Amphibalanus Pitombo, 2004) <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Species Amphitrite Darwin, 1854

Classification adapted from [|ITIS]and Pitombo (2004).

DIAGNOSIS
<span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Darwin (1854) initially described //Balanus amphitrite// as multivariate species of which he had named //B. amphitrite// and identified other eight varieties namely //Balanus amphitrite// var. //communis//, //venustus, pallidus, niveus, modestus, stutsburi, obscurus, variegatus,// and //cirratus//. All of them shared the following morphological and anatomical characteristics of the following: <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Shell longitudinally striped with purple or pink; sometimes with the stripes confluent; sometimes wholly white. Scutum internally with a prominent broad adductor ridge (Refer to figure below)



___ **DESCRIPTION**

**ADULT MORPHOLOGY** ====<span style="font-family: Arial,Helvetica,sans-serif; font-size: 80%;"><span style="font-family: Arial,Helvetica,sans-serif;">(Kindly refer to [|Fox's Guide to Invertebrate Anatomy Online] for reference of morphological terms of a Balanomorph barnacle. ) ==== ====<span style="color: #231f20; font-family: Arial,Helvetica,sans-serif; font-size: 12px;">**Shell**: Wall of six plates, smooth; parietes with a single row of tubes with or without transverse septa; radii solid, transverse teeth on sutural edge with denticles on lower side only (Pitombo, 2004) ====

====<span style="color: #231f20; font-family: Arial,Helvetica,sans-serif; font-size: 12px;">**Operculum**: Scutum with a conspicuous adductor ridge. Tergum with spur having abrupt change in the direction of growth lines, with spur and furrow margins coincident, basal margin with well-developed depressor muscle crests projecting beyond border. ====

====<span style="color: #231f20; font-family: Arial,Helvetica,sans-serif; font-size: 12px;">**Oral cone**: Second maxilla withanterior margin of distal lobe having smooth, acuminate setae with enlarged and modified tips. ====

<span style="color: #231f20; font-family: Arial,Helvetica,sans-serif; font-size: 12px;">**Cirri (feet-like appendages)**: Cirrus III with inner face of endopod with pinnate setae rarely with bifurcate (complex) setae. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Cirri <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;"> IV-VI with erect hooks below posterior angles of distal articles of rami.



FEEDING HABITS
====<span style="font-family: 'Arial','sans-serif'; font-size: 13.3333px;">When submerged in water, //B. amphitrite//, like other balanomorph barnacles, cast out cirri for feeding. There are two forms of feeding, macro-feeding and micro-feeding ====

<span style="font-family: 'Arial','sans-serif'; font-size: 13.3333px;">Macro-feeding/ Captorial feeding
====<span style="font-family: 'Arial','sans-serif'; font-size: 13.3333px;">During macro-feeding, and //B. amphitrite//, withdraw out its cirri and grabs food particles rhymtically at high beat (Crisp & Southward, 1961). Usually larger cirri are usually employed for this method of feeding and range of food size captured from this method are usually in millimeters, for example proteinaceous materials and planktons. ==== ====<span style="color: #000000; font-family: 'Arial','sans-serif'; font-size: 13.3333px;"> [|Watch] a short of clip of macro-feeding by an adult //Balanus amphitrite// (courtesy of Youtube User, platypus1979 ) ====

<span style="font-family: 'Arial','sans-serif'; font-size: 13.3333px;"> Micro-feeding/ Filter-feeding
====<span style="font-family: 'Arial','sans-serif'; font-size: 13.3333px;">Cirri acts as an filter that filters smaller food particles, usually several microns in size, for example diatoms (Crisp & Southward, 1961). Smaller cirri is used as opposed to large cirri. Cirri outside the oral cavity are relatively perpendicular to flow of water (La Barbera, 1984). This form of feeding is less efficient due to slow filtration rates. ====

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">**BIOFOULING**



LIFE HISTORY AND REPRODUCTION
<span style="color: #231f20; font-family: Arial,Helvetica,sans-serif; font-size: 11.6px;">There is no specific mention on the life history of //Balanus amphitrite//. It is assumed that its life history are similar to most balanamorph barnacles (Charnov, 1987). Their life cycle consists of four main stages, (1) egg (released from adult), (2) planktonic nauplius (six-stages, more detailed description of each stage [|here]), (3) cypris larva and (4) attached and sessile adult (Refer to figure below).

//Balanus amphitrite// is hermaprodhite (Darwin, 1854) however <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">one individual usually cross-fertilises with another individual (Charnov, 1987) The penis in a barnacle is extensible, highly maneuvreable, and can extend several body diameters.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">VIdeo on sessile barnacle mating, [|click here]



DISTRIBUTION
<span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">//Balanus amphitrite// was found to be originated from the Southwestern Pacific and Indian Oceans (Zullo 1963). It is distinctly euryhaline and eurythermal in its tolerance (

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Warmer temperate and tropical seas and intertidal beaches ; extremely common; Mediterranean, Smyrna, Sicily, Coast of Portugal, West Coast of Africa, River Gambia, West Indies, Demerara, Natal, Madagascar, Red Sea, Mouth of the Indus, Ceylon, Philippine Archipelago, East Indian Archipelago, Pacific Ocean, east coast of Australia, New Zealand; extremely common on ships' bottoms; often attached to floating timber, canes, &c.; often associated with //B. tintinnabulum;//attached to pebbles and various shells Darwin (1854).

=Invasion= Although expected to be confined to warm and tropical waters, //B. amphitrite// was found to be invasive in several colder and temperate countries including[| Northern America (United States of America)], Southern America (Argentina)(Oresanz //et al//., 2002), Europe (Germany)<span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;"> (Wiegemann, 2008), Northeast Asia (Japan and Hong Kong) (Qiu, 1999) and Oceania (Australia ands New Zealand) (Foster, 1978).

TYPE INFORMATION
<span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Darwin (1854) did not designate type specimens and type localities for //B. amphitrite// and its varieties (Yamaguchi, 1980). However, the original specimen that was studied by Darwin was kept in the British Museum (Harding, 1961). Such a specimen without designation of type specimen is termed a lectotype. The lectotype was originally found on a piece of bamboo (Registration No. :B. M. 40.9.15.17, locality Natal, Dr. Krauss) however its dissected parts keep seperately. Now, its remaining shell on the bamboo has been registered as B.M. 1961. 12. 6. 1c, seperated and mounted opercular valve as B.M. 1961.12.6. 1a and animal parts as B.M. 1961.12.6. 1b (Harding, 1961).

Literature and References
Click [|here] page 240) for the original description of //Balanus amphitrite// by Charles Darwin.

Anderson, D. T. 1980. Barnacles - structure, function, development and evolution. Chapman and Hall London.

Darwin, C. R. 1854. //Living Cirripedia, The Balanidæ, (or sessile cirripedes); the Verrucidæ//. London: The Ray Society. Volume 2 [|Text] [|Image] [|Text & image] F339.2

<span style="color: #231f20; font-family: 'Arial','sans-serif'; font-size: 16px;"><span style="color: #231f20; font-family: Arial,Helvetica,sans-serif; font-size: 12px;">Charnov, E.L. 1987. Sexuality and hermaphroditism in barnacles: a natural selection approach. In Southward A.J. (ed.) Crustacean issues 5, Barnacle biology. Rotterdam: A.A. Balkema, pp. 89–104.

Clare, A.S., and Høeg. J.T.. 2008. “Balanus amphitrite or Amphibalanus amphitrite? A note on barnacle nomenclature.” //Biofouling// **24**(1): 55-7.

Foster, B.A. 1978. The marine fauna of New Zealand: Barnacles (Cirripedia, Thotacica). Memoirs of the New Zealand Oceanographic Institute 69: 1-160.

Henry, D. P. & Mclaughlin, P. A. (1975). The barnacles of the. Balanus amphitrite complex (Cirripedia, Thoracica). Zoologische. //Verhandelingen//, 141, 1–254

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">LaBarbera, M. 1984. "Feeding currents and particle capture mechanisms in suspension feeding animals". //American Zoologist// **24** (1): 71–84.

=
<span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Lulito, C. 2007.Distribution, abundance and reproduction of the Indo-Pacifric acorn barnacle Balanus amphitrite (Crustacea: Cirripedia). J. Mar. Biol. Ass. U.K., **87**: 723-727 =====

Orensanz, J.M., Schwindt, E., Pastorino, G., Bortulas, A., Casas, G., Darrigan, G., Elías, R., Gappa, J.J.L., Obenat, S., Pascual, M., Penchaszadeh, P., Piriz, M.L., Scabarino, F., Spivak, E.D. and E.A. Vallarino. 2002. No longer the pristine confines of the world ocean: a survey of exotic marine species in the southwestern Atlantic. //Biological Invasions,// **4**: 115-143.

Pitombo, F. B. 2004. Phylogenetic analysis of the Balanidae (Cirripedia, Balanomorpha). Zoologica Scripta, 33: 261–276.

<span style="font-family: 'Arial','sans-serif'; font-size: 13.3333px;">Qiu, J.W. 1999. Tolerance of the barnacle //<span style="font-family: 'Arial','sans-serif'; font-size: 13.3333px;">Balanus Amphitrite amphitrite //<span style="font-family: 'Arial','sans-serif'; font-size: 13.3333px;">to salinity and temperature stress:effects of previous experience. //Marine Ecology Progress Series//. 188. 123-132

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Wiegemann, M. 2008. Wild cyprids metamorphosing in vitro reveal the presence of //Balanusamphitrite// Darwin, 1854 in the German Bight basin, //Aquatic Invasions//, 3(2): 235-238.

<span style="font-family: Arial,Helvetica,sans-serif;">Yamaguchi, T. 1980. A New Species Belonging to the //Balanus amphitrite// Darwin Group (Cirripedia, Balanomorpha).//Journal of Paleontology//, **54**(5): 1084-1101

<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 90%;">Zullo, V. A. 1963. A Preliminary Report On Systematics And Distribution Of Barnacles (Cirripedia) Of Cape Cod Region. Systematics-Ecology Program, Marine Biology Laboratory, Woods Hole, Massachusetts, 33 p


 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 140%;">Links to other types of species pages **

http://www.marinespecies.org/aphia.php?p=taxdetails&id=415046

http://www.exoticsguide.org/species_pages/b_amphitrite.htmltoc flat