elphidium elphidium elphidium is an abundant genus of foraminifera. species can be found from coastal regions out to the continental slope, and in all temperature ranges. like other forams, fossils from different species are used to date rocks. the taxonomy of the species within this genus is disputed due to the high variability of some species. elphidiumtemporal range: early eocene to holocene elphidium excavatum clavatum scientific classification domain: eukaryota clade: diaphoretickes clade: sar phylum: retaria infraphylum: foraminifera class: globothalamea order: rotaliida family: elphidiinae genus: elphidiummontfort, 1808 subgenera and species see text synonyms andromedes montfort, 1808 (opinion of loeblich & tappan, 1987) canalifera krasheninnikov, 1953 (name not available iczn art. 13(a)(i)) carpenterella krasheninnikov, 1953 (opinion of loeblich & tappan, 1987) cellanthus montfort, 1808 cellulia agassiz, 1844 (opinion of loeblich & tappan, 1987, err. emend.) cribrononion thalmann, 1947· accepted, alternate representation faujasinella voloshinova, 1958 (subjective junior synonym in opinion of loeblich & tappan, 1987) geophonus montfort, 1808 (opinion of loeblich & tappan, 1987) helicoza mobius, 1880 (opinion of loeblich & tappan, 1987) helicoza möbius, 1880 (opinion of loeblich & tappan, 1987) nonion (cribrononion) thalmann, 1947 (opinion of loeblich & tappan, 1987) ozawaia cushman, 1931 (junior subjective synonym in opinion of hayward et al. (1997)) perfectononion voloshinova & leonenko, 1970 (opinion of loeblich & tappan, 1987) planoelphidium voloshinova, 1958 (opinion of loeblich & tappan, 1987) polystomatium ehrenberg, 1839 (opinion of loeblich & tappan, 1987) polystomella lamarck, 1822 (subjective junior synonym opinion of loeblich and tappan (1987)) sporilus montfort, 1808 (opinion of loeblich & tappan, 1987) themeon montfort, 1808 (opinion of loeblich & tappan, 1987) vorticialis lamarck, 1812 (opinion of loeblich & tappan, 1987) description elphidium is generally around 1 mm in size. the test is spiral-shaped, and can be red, orange, or brown. this shell is made up of calcium carbonate. species of this genus have seven to twenty chambers in the final whorl, and may have an umbilical plug on each side. in some species the rim is sharp, while in others it is more rounded. another distinctive feature is the retral processes (small backward extensions of the chamber walls) that cross the sutures, giving some the appearance of tiny rolled up glass baskets. elphidium crawls using a type of pseudopod called reticulopodia. life cycle elphidium shows dimorphism with alternating generations. the complete cycle for elphidium crispum takes two years in the shallower marine regions, although it may be delayed at deeper stations. asexual reproduction reaches a peak in spring of the first year. sexual reproduction begins early in the second spring as temperatures begin to rise. the gametes conjugate outside in open sea to produce zygotes and the b form then develops and matures during the second summer. lister (1895) observed elphidium in two different forms as megalospheric form (sexual form) and microsperic form (asexual form). the megalosperic form was developed from the microsperic form. the gametes which gives rise to microspheric form by syngamy. elphidium exhibits an alternation of generation in its life cycle. the megalosperic forms alternates with microspheric forms. the microspheric forms are developed by the conjugation or syngamy. it means there is always an alternations of asexual (microspheric) and sexual (megalospheric) generation in elphidium. the microspheric form reproduces asexually by fission to produce a number of amoebulae. the inner cytoplasm mass containing several nuclei creeps out of the shell and remains as a lump around it. a small amount of cytoplasm collects around each nucleus. as a result, a large number of amoeboid cells are formed. each amoebula secretes the proloculum, formsrhizopodia, then it grows and forms other chambers of the shell to become a megalospheric forms. the megalospheric form reproduces sexually by syngamy or conjugation. during sexual reproduction in megalospheric forms, nucleus first breaks up into many small nuclei and the cytoplasm collects around each of these nuclei. the nuclei divide twice giving rise to a large haploid and known as isogametes. isogametes of two different individuals fuse in pairs to form zygotes. these are then develops into microspheric form. the life cycle of elphidium may be summarized as follows: the microspheric forms produce amoebulae by asexual fission which develops into megalospheric forms. the megalospheric forms produce flagellated isogametes which after syngamy produce zygotes that develop into microspheric forms. thus, its life cycle clearly exhibits the phenomenon of alternations of asexual microspheric generations with sexual megalospheric generations. subdivisions subgenus elphidium (parrellina) carter, 1958 †elphidium (parrellina) centrifugalis carter, 1958 subgenus elphidium (polystomella) heron-allen & earland, 1932 elphidium incertae sedis elphidium abyssicola ishiwada, 1964 elphidium aculeatum (d'orbigny, 1846) †elphidium adelaidense howchin & parr, 1938 elphidium advenum (cushman, 1922) †elphidium africanum leroy, 1953 †elphidium aguafrescaense todd & kniker, 1952 elphidium alaskense cushman & todd, 1947 elphidium albanii hayward, 1997 in hayward, hollis & grenfell, 1997 elphidium alvarezianum (d'orbigny, 1839) †elphidium ancestrum le calvez, 1950 elphidium argenteum parr, 1945 †elphidium armenium saakyan-gezalyan, 1957 elphidium articulatum (d'orbigny, 1839) †elphidium asagaiense asano, 1949 †elphidium asanoi kaiho, 1984 †elphidium asanoi matsunaga, 1963 elphidium asiaticum polski, 1959 elphidium asklundi brotzen, 1943 †elphidium australis cushman & parker, 1931 †elphidium azerbaidjanicum mamedova, 1966 †elphidium aznaburticum pronina, 1964 elphidium bartletti cushman, 1933 elphidium batavum hofker, 1968 elphidium batialis saidova, 1961 †elphidium bhattacharyai jauhri, 1994 elphidium biperforatus (whittaker & hodgkinson, 1979) †elphidium bogdanowiczi pronina, 1964 elphidium bosoense fujita, 1956 elphidium botaniense albani, 1981 †elphidium brooklynense shupack, 1934 †elphidium californicum cook ms., 1959 elphidium capelavelaense mcculloch, 1981 †elphidium carenerosensis bermúdez & fuenmayor, 1966 †elphidium cariacoense bermúdez & seiglie, 1963 elphidium carpentariaense albani & yassini, 1993 elphidium carteri hayward, 1997 in hayward, hollis & grenfell, 1997 †elphidium cercadense bermúdez, 1949 †elphidium chapmani cushman, 1936 elphidium charlottense (vella, 1957) †elphidium cherifi anan, 2010 †elphidium chilenum todd & kniker, 1952 †elphidium clarki graham, 1950 †elphidium clavatum cushman em. loeblich & tappan, 1953 elphidium cochense mcculloch, 1981 elphidium collinsi hayward, 1997 in hayward, hollis & grenfell, 1997 elphidium colomboense mcculloch, 1977 †elphidium colomi ferrer, 1971 elphidium complanatum (d'orbigny, 1839) †elphidium compressulum copeland, 1964 †elphidium concinnum khalilov, 1957 †elphidium concinnum nicol, 1944 †elphidium consociatum khalilov, 1957 †elphidium costiferum (terquem, 1882) †elphidium crassatum cushman, 1936 elphidium crassimargo shchedrina, 1984 elphidium craticulatum (fichtel & moll, 1798) †elphidium crespinae cushman, 1936 elphidium crispum (linnaeus, 1758) elphidium cristobalense mcculloch, 1981 elphidium cubaguaense mcculloch, 1981 †elphidium culebrense cushman, 1936 elphidium cuvillieri levy, 1966 †elphidium cynicalis jennings, 1936 elphidium decipiens (o.g.costa, 1856) †elphidium decorum qiu & lin, 1978 †elphidium deferrariisi malumián, 1990 elphidium delicatulum bermúdez, 1949 elphidium discoidale (d'orbigny, 1839) †elphidium dominicense bermúdez, 1949 †elphidium dopperti daniels, 2001 †elphidium duzdagicum pronina, 1964 elphidium earlandi cushman, 1936 †elphidium echinus serova, 1955 †elphidium elegans serova, 1955 elphidium elegantum (hofker, 1976) †elphidium ellisi weiss, 1954 †elphidium eocenicum cushman & ellisor, 1931 elphidium excubitor nicol, 1944 elphidium exoticum haynes, 1973 †elphidium ezoense asano, 1937 †elphidium fastigiatum cushman, 1945 elphidium fax nicol, 1944 †elphidium fedorowi bogdanovich, 1960 †elphidium felsense papp, 1963 †elphidium ferrentegranulum krasheninnikov, 1960 elphidium fichtelianum (d'orbigny, 1846) elphidium fijiense hayward, 1997 in hayward, hollis & grenfell, 1997 elphidium fimbriatulum (cushman, 1918) †elphidium fissurisuturalum wang, he & lu, 1988 †elphidium flexuosum (d'orbigny, 1846) †elphidium florentinae shupack, 1934 †elphidium formosum todd, 1957 †elphidium friedbergi serova, 1955 elphidium frigidum cushman, 1933 elphidium frizzelli miller, 1953 elphidium galvestonense kornfeld, 1931 †elphidium georgianum cushman, 1935 †elphidium georgium venglinsky, 1958 †elphidium gibsoni hayward, 1979 †elphidium glabratum cushman, 1939 †elphidium granatum gudina, 1964 †elphidium granti kleinpell, 1938 elphidium granulosum (sidebottom, 1909) †elphidium grimensis quilty, 1980 elphidium groenlandicum cushman, 1933 †elphidium guraboense bermúdez, 1949 †elphidium haagensis van voorthuysen, 1950 †elphidium hadleyana smitter, 1955 elphidium halickii brodniewicz, 1972 elphidium hallandense brotzen, 1943 †elphidium hampdenense finlay, 1939 †elphidium hauerinum (d'orbigny, 1846) elphidium hawkesburyense (albani, 1974) †elphidium helenae quilty, 1980 †elphidium hiltermanni hagn, 1952 elphidium hispidulum cushman, 1936 elphidium hokkaidoense asano, 1950 †elphidium hornibrooki srinivasan, 1966 †elphidium howchini cushman, 1936 elphidium hughesi cushman & grant, 1927 †elphidium humboldtensis haller, 1980 †elphidium hungaricum korecz-laky, 1967 elphidium hyalocostatum todd, 1957 †elphidium ibericum (schrodt, 1890) †elphidium icenorum macfadyen, 1939 elphidium inchonense mcculloch, 1977 †elphidium inclarum krasheninnikov, 1960 elphidium indicum cushman, 1936 †elphidium infrajuliense bertels, 1977 †elphidium ingressans dorreen, 1948 †elphidium inopinatum khalilov, 1957 †elphidium iojimaense asano & murata, 1958 elphidium iranicum (yassini & ghahreman, 1977) †elphidium ishikariense kaiho, 1984 †elphidium izumoense nomura, 1990 †elphidium javanum yabe & asano, 1937 elphidium jiani lei & li, 2016 †elphidium johnstonae mclean, 1956 †elphidium joukovi serova, 1955 †elphidium kadilnicovi semenov & semenova, 1980 †elphidium kaicherae mclean, 1956 elphidium kaneharai ishiwada, 1958 †elphidium kanoum hayward, 1979 †elphidium karenae asbjornsdottir, 1994 †elphidium karpaticum myatlyuk, 1950 †elphidium kazmakrisense mamedova, 1966 elphidium kerguelenense parr, 1950 elphidium kobense mcculloch, 1977 †elphidium koberi tollmann, 1955 elphidium koeboeense leroy, 1939 elphidium kozlowskii brodniewicz, 1965 †elphidium kudakoense bogdanovich, 1947 elphidium kusiroense asano, 1938 †elphidium laeve (d'orbigny in parker, jones & brady, 1865) elphidium lagunense (albani & balbero, 1982) †elphidium laloviensis venglinsky, 1948 elphidium lanieri (d'orbigny, 1839) †elphidium latidorsatum (reuss, 1864) †elphidium latispatium poag, 1966 †elphidium latusovum krasheninnikov, 1960 †elphidium lauritaense todd & kniker, 1952 †elphidium lautenschlaegeri voloshinova, 1952 elphidium lene cushman & mcculloch, 1940 †elphidium lens galloway & heminway, 1941 †elphidium leonensis applin & jordan, 1945 elphidium lessonii (d'orbigny, 1839) †elphidium ligatum krasheninnikov, 1960 †elphidium limatulum copeland, 1964 elphidium limpidum ho, hu & wang, 1965 †elphidium lobatum galloway & heminway, 1941 †elphidium ludbrookae bhalla & dev, 1988 †elphidium mabutii asano, 1962 elphidium macellum (fichtel & moll, 1798) elphidium maioricense colom, 1942 †elphidium manibulum khalilov, 1957 elphidium maorium hayward, 1997 elphidium margaritaceum cushman, 1930 †elphidium marshallana todd & post, 1954 elphidium matagordanum (kornfeld, 1931) †elphidium matanginuiense hayward, 1997 †elphidium matauraense hayward, 1997 †elphidium matsuense nomura, 1990 elphidium matsukawauraense takayanagi, 1955 elphidium mawsoni parr, 1950 elphidium mexicanum kornfeld, 1931 †elphidium microelegans serova, 1955 †elphidium microgranulosum galloway & wissler, 1951 †elphidium miikense murata, 1961 elphidium millettiforme mcculloch, 1977 †elphidium minutum (reuss, 1865) †elphidium mirandum krasheninnikov, 1960 †elphidium mironovi voloshinova, 1952 elphidium morenoi bermúdez, 1935 elphidium mortonbayense albani & yassini, 1993 †elphidium multacamerum krasheninnikov, 1960 †elphidium mundulum todd & low, 1960 †elphidium musselroeensis quilty, 1980 †elphidium nagaoi asano, 1938 elphidium nakanokawaense shirai, 1960 †elphidium nataliae popescu, 1995 †elphidium nautiloideum galloway & heminway, 1941 †elphidium neocrespinae gibson, 1983 elphidium neosimplex mcculloch, 1977 †elphidium nigarense cushman, 1936 †elphidium nipeense keijzer, 1945 †elphidium noniformis gerke in voloshinova & dain, 1952 †elphidium nonioniformis smigielska, 1957 elphidium norvangi buzas, smith & beem, 1977 †elphidium notabilis pishvanova, 1958 elphidium novozealandicum cushman, 1936 †elphidium obtusum (d'orbigny, 1846) elphidium oceanense (d'orbigny in fornasini, 1904) elphidium oceanicum cushman, 1933 †elphidium oligocenicum khalilov, 1951 †elphidium ombetsuense asano, 1962 †elphidium omotoensis dorreen, 1948 elphidium omuraense shuto, 1953 †elphidium onerosum bogdanovich, 1960 †elphidium orientale voloshinova, 1952 elphidium owenianum (d'orbigny, 1839) elphidium ozawai uchio, 1951 †elphidium panamense cushman, 1936 †elphidium papillosum cushman, 1936 †elphidium paraense petri, 1954 †elphidium paraskevaidisi christodoulou, 1960 elphidium parviforme mcculloch, 1981 †elphidium parvulum aoki, 1968 elphidium parvum zheng, 1980 †elphidium parvus eremeeva, 1961 †elphidium patagonicum todd & kniker, 1952 †elphidium perforatum nomura, 1990 †elphidium perscitum serova, 1955 †elphidium philippense hayward, 1997 elphidium phillipense hayward, 1997 in hayward, hollis & grenfell, 1997 elphidium pilasense mcculloch, 1977 elphidium planiforme mcculloch, 1981 elphidium planulatum (lamarck, 1822) elphidium planum husezima & maruhasi, 1944 †elphidium podolicum serova, 1955 elphidium ponticum (dolgopolskaya & pauli, 1931) †elphidium primum ten dam, 1944 elphidium pseudoinflatum cushman, 1936 †elphidium pseudolessonii ten dam & reinhold, 1941 †elphidium pseudonodosum cushman, 1936 †elphidium puertoricense galloway & heminway, 1941 elphidium pulvereum todd, 1958 elphidium punctatum (terquem, 1878) †elphidium puscharovski serova, 1955 †elphidium pusillogranosum venglinsky, 1958 †elphidium pustulisuturale wang & cheng, 1981 elphidium pustulosum cushman & mcculloch, 1940 †elphidium rarum husezima & maruhasi, 1944 †elphidium rasshamali haque, 1970 †elphidium reginum (d'orbigny, 1846) elphidium reticulosum cushman, 1933 †elphidium rioturbiense malumián, 1994 †elphidium rischtanicum bykova, 1939 †elphidium rolshauseni cushman & ellisor, 1939 †elphidium rota ellis, 1939 elphidium rotatum howchin & parr, 1938 †elphidium rugosum (d'orbigny, 1846) elphidium rugulosum cushman & wickenden, 1929 elphidium rutteni hermes, 1945 †elphidium saginatum finlay, 1939 elphidium sagrum (d'orbigny, 1839) †elphidium saitoi asano & murata, 1958 †elphidium salebrosum serova, 1955 †elphidium samueli zlinská, 1993 elphidium sandiegoense (lankford, 1973) †elphidium sandongensis he & hu, 1978 †elphidium schencki cushman & dusenbury, 1934 †elphidium schreiteri eichenberg, 1935 †elphidium semiinvolutum myatlyuk, 1956 elphidium semistriatum (d'orbigny, 1852) †elphidium sendaiense takayanagi, 1950 †elphidium seranense valk, 1945 elphidium seymourense mcculloch, 1977 elphidium shochinae mayer, 1968 elphidium silvestrii hayward, 1997 in hayward, hollis & grenfell, 1997 elphidium simaense makiyama & nakagawa, 1941 elphidium simulatum mcculloch, 1977 elphidium singaporense mcculloch, 1977 †elphidium skyringense todd & kniker, 1952 †elphidium smithi cushman & dusenbury, 1934 elphidium somaense takayanagi, 1955 elphidium spinatum cushman & valentine,