小塔螺科[2]（学名：Pyramidellidae），亦作尖塔螺科或简单只叫塔螺科，是软体动物门腹足纲下的一个科。旧属肠纽目（Heterostropha，又译异旋目）[2]，成员主要是营寄生生活的小型海螺。
小塔螺科的物种分布于整个世界，有超过六千个不同的物种，合组成超过350个属与亚属[3]。由于本科物种皆属于微小贝，相关研究少，物种间支序亲缘关系并不十分清楚，大众对于各物种的归属也没有共识。举例说：单单是 Schander (1999) 就列出了超过300个属级以上的分类单元命名，并将这些分类单元整理[4]。由于近年本科在世界各地各个属的分类未再有可一般化的修订，这个科内各个分类单元仍然保持是多系群，也就是说这些分类的混乱还有一段时间。然而，从整个科来看仍然是个单系群[5]。
本科物种主要分为11个亚科（Ponder & Lindberg 1997）[6]。An alternative interpretation is that the family Pyramidellidae is but one of six families within the superfamily Pyramidelloidea (Schander, van Aartsen & Corgan 1999).[7]
当中有不少罕见或不常纪录的物种。
本科之下的亚科在不同年代刊行的分类学文献都有所不同，当中最为普遍的分类是2005年的布歇特和洛克罗伊的腹足类分类[8]。以下详列自1997年以来多个分类间的差异。
在1997年的旁得和林德伯格的腹足类分类，本科的分类如下[6]：
- Chrysallidinae Saurin, 1958
- Cingulininae Saurin, 1959
- Cyclostremellinae Moore, 1966
- Eulimellinae Saurin, 1958
- Odostomellinae Saurin, 1959
- Odostomiinae Pelseneer, 1928
- Pyramidellinae J.E. Gray, 1840
- Sayellinae Wise, 1996
- Syrnolinae Saurin, 1958
- Tiberiinae Saurin, 1958
- Turbonillinae Bronn, 1849
Taxonomy of Pyramidellidae by Schander, Van Aartsen & Corgan (1999):[7]
- Superfamily Pyramidelloidea Gray, 1840
- Family Amathinidae Ponder, 1987
- Family Ebalidae Warén, 1994 - synonym: Anisocyclidae van Aartsen, 1995
- Family Odostomiidae Pelseneer, 1928
- Subfamily Odostomiinae Pelseneer, 1928
- Subfamily Chrysallidinae Saurin, 1958
- Subfamily Odostomellinae Saurin, 1958
- Subfamily Cyclostremellinae Moore, 1966
- Family Pyramidellidae J. E. Gray, 1840
- Subfamily Pyramidellinae J. E. Gray, 1840
- Subfamily Sayellinae Wise, 1996
- Family Syrnolidae Saurin, 1958
- Subfamily Syrnolinae Saurin, 1958
- Subfamily Tiberiinae Saurin, 1958
- Family Turbonillidae Bronn, 1849
- Subfamily Turbonillinae Bronn, 1849
- Subfamily Eulimellinae Saurin, 1958
- Subfamily Cingulininae Saurin, 1959
在2005年《布歇特和洛克罗伊的腹足类分类》，原来小塔螺总科之下的各科均被降级成为新的小塔螺科的亚科；而各科之下的亚科亦变成了各个亚科之下的族。这些变更总结如下[8]：
- Subfamily Pyramidellinae Gray, 1840
- Tribe Pyramidellini Gray, 1840 - synonyms: Obeliscidae A. Adams, 1863 (inv.); Plotiidae Focart, 1951 (inv.)
- Tribe Sayellini Wise, 1996 - formerly subfamily Sayellinae
- Subfamily Odostomiinae Pelseneer, 1928
- Tribe Odostomiini Pelseneer, 1928 - synonyms: Ptychostomonidae Locard, 1886; Liostomiini Schander, Halanych, Dahlgren & Sundberg, 2003 (n.a.)
- Tribe Chrysallidini Saurin, 1958 - formerly subfamily Chrysallidinae, synonyms: Menesthinae Saurin, 1958; Pyrgulininae Saurin, 1959
- Tribe Cyclostremellini D. R. Moore, 1966 - formerly subfamily Cyclostremellinae
- Tribe Odostomellini Saurin, 1959 - formerly subfamily Odostomellinae
- Subfamily Syrnolinae Saurin, 1958 - formerly subfamily Syrnolinae
- Tribe Syrnolini Saurin, 1958
- Tribe Tiberiini Saurin, 1958 - formerly subfamily Tiberiinae
- Subfamily Turbonillinae Bronn, 1849
- Tribe Turbonillini Bronn, 1849 - synonym: Chemnitziinae Stoliczka, 1868
- Tribe Cingulinini Saurin, 1958 - formerly subfamily Cingulininae
- Tribe Eulimellini Saurin, 1958 - formerly subfamily Eulimellinae
- Pyramidellidae incertae sedis
- Pyramidellidae incertae sedis insularis Oliver, 1915
- Pyrabinella Faber, 2013
2010年，本科得到确认为单系群[9]。
2017年，栖息于中南太平洋深海的塔螺总科新属Helodiamea属 Peñas & Rolán, 2017得到确认[10]。
截至2018年7月9日 (2018-07-09)[update]，WoRMS纪录小塔螺科包括下列各亚科与族[11]：
- Subfamily Cyclostremellinae D. R. Moore, 1966
- Subfamily Odostomiinae Pelseneer, 1928
- Tribe Chrysallidini Saurin, 1958
- Tribe Cyclostremellini D. R. Moore, 1966
- Tribe Odostomiini Pelseneer, 1928
- Subfamily Pyramidellinae
- Tribe Pyramidellini Gray, 1840
- Tribe Sayellini Wise, 1996
- Subfamily Syrnolinae Saurin, 1958
- Tribe Syrnolini Saurin, 1958
- Tribe Tiberiini Saurin, 1958
- Subfamily Turbonillinae Bronn, 1849
The following genera are currently difficult to place within existing subtaxa of the Pyramidellidae.
- Charilda Iredale, 1929
- Contraxiala Laseron, 1956
- Cossmannica Dall & Bartsch, 1904[来源请求]
- Eulimotibera Nomura, 1939[来源请求]
- Morrisonetta Brandt, 1968[来源请求]
- Peristichia Dall, 1889[12]
- Ulfa Dall & Bartsch, 1904[来源请求]
- Vagna Dall & Bartsch, 1904[来源请求]
The following species is of uncertain placement within Pyramidellidae.
- "Epigrus" insularis Oliver, 1915
下列为本科分类单元的异名：
- Actaeopyramis P. Fischer, 1885: synonym of Monotigma G.B. Sowerby II, 1839
- Amaura Møller, 1842: synonym of Aartsenia Warén, 1991
- Auriculina Gray, 1847 accepted as Ondina de Folin, 1870
- Besla Dall & Bartsch, 1904 accepted as Parthenina Bucquoy, Dautzenberg & Dollfus, 1883
- Brachystomia Monterosato, 1884: synonym of Odostomia Fleming, 1813
- Chemnitzia d'Orbigny, 1839: synonym of Turbonilla Risso, 1826
- Elusa A. Adams, 1861: synonym of Tropaeas Dall & Bartsch, 1904
- Folinella Dall & Bartsch, 1904: synonym of Chrysallida Carpenter, 1856
- Iole A. Adams, 1860: synonym of Iolaea A. Adams, 1867
- Iolina Baily, 1948: synonym of Iolaea A. Adams, 1867
- Ividella Dall & Bartsch, 1909 accepted as Chrysallida Carpenter, 1856
- Lonchaeus : synonym of Longchaeus Mörch, 1875
- Moerchiella Thiele, 1924 : synonym of Moerchia A. Adams, 1860
- Moerchinella Thiele, 1931 accepted as Moerchia A. Adams, 1860
- Monoptygma: synonym of Monotigma G.B. Sowerby II, 1839
- Monotygma G.B. Sowerby II, 1839: synonym of Monotigma G.B. Sowerby II, 1839
- Noemia de Folin, 1870: synonym of Noemiamea de Folin, 1886
- Obeliscus Gray, 1847: synonym of Pyramidella Lamarck, 1799
- Obex Laws, 1940 accepted as Obexomia Laws, 1941
- Odontostoma Philippi, 1853: synonym of Odostomia Fleming, 1813
- Odontostomia G.B. Sowerby I, 1839: synonym of Odostomia Fleming, 1813
- Parthenia Lowe, 1840: synonym of Parthenina Bucquoy, Dautzenberg & Dollfus, 1883
- Parthenina Bucquoy, Dautzenberg & Dollfus, 1883: synonym of Chrysallida Carpenter, 1856
- Partulida Schaufuss, 1869: synonym of Chrysallida Carpenter, 1856
- Planipyrgiscus [sic] accepted as Planpyrgiscus Laws, 1937
- Plotia Röding, 1798: synonym of Pyramidella Lamarck, 1799
- Ptychostomon Locard, 1886 accepted as Odostomia Fleming, 1813
- Pyrgulina A. Adams, 1864: synonym of Chrysallida Carpenter, 1856
- Raoulostraca Oliver, 1915 accepted as Eulimella Forbes & M'Andrew, 1846
- Tragula Monterosato, 1884: synonym of Chrysallida Carpenter, 1856
- Tropeas [sic] accepted as Tropaeas Dall & Bartsch, 1904
本物种有世界性分布，但当中不少物种都只在相当细小范围内分布。在佛得角的各物种均为当地的特有种[13]。
The length of the slender, elongated (turreted or conical) shells varies between 0.5 mm and 3.5 cm, but most species in the family have shells which are smaller than 13 mm.
The texture of these shells is smooth or sculptured in various forms such as ribs and spirals. Their color is mostly white, cream or yellowish, sometimes with red or brown lines.
The shell of these snails has a blunt, heterostrophic (i.e. whorls appear to be coiled in the opposite direction to those of the teleoconch) protoconch, which is often pointed sideways or wrapped up. The teleoconch is dextrally coiled, but the larval shells are sinistral. This results in a sinistrally coiled protoconch.
The columella has usually one, but sometimes several, spiral folds. The aperture is closed by an operculum.
The operculum is ovoid and paucispiral, with the apex anterior, a thread-like arcuate ridge on the proximal side, the inner margin notched in harmony with the plaits of the pillar when prominent.
The Pyramidellidae are ectoparasites, feeding mainly on other molluscs and on annelid worms, but some are known to feed on peanut worms and crustaceans.[14][15]
A few species in the family Pyramidellidae, such as Otopleura mitralis, are symbiotic with sea anemones, such as Neoaiptasia morbilla.[16]
They do not have a radula. Instead their long proboscis is used to pierce the skin of its prey and suck up its fluids and soft tissues. The eyes on the grooved tentacles are situated toward the base of the tentacles. These tentacles have a concave surface. Between the head and the propodium (the foremost division of the foot), a lobed process called the mentum (= thin projection) is visible. This mentum is slightly indented in midline.
These gastropods are hermaphrodites, laying eggs in jelly-like masses on the shell of its host. Some species have spermatophores.[4][17][18]
本科的学名源于金字塔的英语pyramid，而这亦是这些物种普遍的外型[19]。
准确点说：这些物种都呈正圆锥体的模样[20]，又或是正多边形的锥体[21]。
Gray, J. E. Synopsis of the contents of the British Museum, 42nd edition. London. 1840: 370 pp.
Schander, Christoffer; Hori, Shigeo; Lundberg, Joakim. Anatomy, phylogeny and biology of Odostomella and Herviera, with the description of a new species of Odostomella (Mollusca, Heterostropha, Pyramidellidae). Ophelia. 2011, 51 (1): 39–76. doi:10.1080/00785326.1999.10409399. Dinapoli, A.; Zinssmeister, C.; Klussmann-Kolb, A. New insights into the phylogeny of the Pyramidellidae (Gastropoda). Journal of Molluscan Studies. 2010, 77 (1): 1–7. doi:10.1093/mollus/eyq027. Ponder, Winston; Lindberg, David R. Towards a phylogeny of gastropod molluscs; an analysis using morphological characters. Zoological Journal of the Linnean Society. 1997, 119 (2): 83–265. doi:10.1111/j.1096-3642.1997.tb00137.x （英语）. Bieler R, Bouchet P, Gofas S, Marshall B, Rosenberg G, La Perna R, Neubauer TA, Sartori AF, Schneider S, Vos C, ter Poorten JJ, Taylor J, Dijkstra H, Finn J, Bank R, Neubert E, Moretzsohn F, Faber M, Houart R, Picton B, Garcia-Alvarez O (编). Pyramidellidae Gray, 1840. MolluscaBase. [2018-07-14] –通过WoRMS. Sneli, J.-A. Odostomia turrita found on Hommarus gammarus. Nautilus. 1972, 86 (1): 23–24.
Høisæter, T. Spermatophores in Chrysallida obtusa (Brown) (Opisthobranchia, Pyramidellidae). Sarsia. 1965, 18: 63–68.
Robertson, R. The life history of Odostomia bisuturalis and Odostomia spermatophores (Gastropoda: Pyramidellidae). American Philosophical Society Yearbook. 1967, 1967: 368–370.
Robbins, Edward. [小塔螺科载于Google图书 Plane and Solid Geometry]. American Book Company. 1907: 349 （英语）.
- Dinapoli A., Zinssmeister C. & Klussmann-Kolb A. (2010). "New insights into the phylogeny of the Pyramidellidae (Gastropoda)". Journal of Molluscan Studies doi:10.1093/mollus/eyq027.
- Hayward P. J. &, J.S. Ryland. Handbook of the Marine Fauna of North-West Europe. Oxford University Press. 1996: 546. ISBN 0-19-854055-8.
