Rissoa
Encyclopedia
Rissoa is a genus
of minute sea snail
s, marine
gastropod mollusks or micromollusk
s in the family
Rissoidae
.
The genus was first introduced by M. de Freminville for some small shells observed by M. Antoine Risso
, a distinguished naturalist of Nice, France. They were described by M. Demarest in 1814 in the "New Bulletin of the Philomatic Society".
. The tentacles are awl-shaped with the eyes on a small prominence near the base. The foot is oval or elliptical. The species is phytophagous.
The conical shell has an elongated spire
with its apex
nipple-shaped. The size of the shell varies between 1 mm and 8 mm. The whorls
are generally convex-shaped with a distinct suture. The aperture
is ovate, roundish or pear-shaped with its anterior end rounded, the posterior end acute and with the peristome
complete. The thin and horny operculum
is spirally marked and equally ovate, roundish or pear-shaped.
), in clefts of rocks, on stones, on mud or sand. Most will be found on sandy beaches along the line of the last tide.
Species brought into synonymy :
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of minute sea snail
Sea snail
Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....
s, marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
gastropod mollusks or micromollusk
Micromollusk
A micromollusk is a descriptive term for a shelled mollusk which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine mollusks, although in addition, numerous species of land snails and freshwater mollusks also reach adult size at very small...
s in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Rissoidae
Rissoidae
Rissoidae is a large family of very small and minute sea snails with an operculum, marine gastropod mollusks in the clade Littorinimorpha.-Distribution and habitat:...
.
The genus was first introduced by M. de Freminville for some small shells observed by M. Antoine Risso
Antoine Risso
Giuseppe Antonio Risso , called Antoine Risso, was a Niçard naturalist.Risso was born in Nice, County of Nice, a part of the Duchy of Savoy, and studied under Giovanni Battista Balbis. He published , and . Risso's dolphin was named after him...
, a distinguished naturalist of Nice, France. They were described by M. Demarest in 1814 in the "New Bulletin of the Philomatic Society".
Description
The soft body of the snail is elongated and spiral. The somewhat prolonged mouth has a proboscisProboscis
A proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In simpler terms, a proboscis is the straw-like mouth found in several varieties of species.-Etymology:...
. The tentacles are awl-shaped with the eyes on a small prominence near the base. The foot is oval or elliptical. The species is phytophagous.
The conical shell has an elongated spire
Spire (mollusc)
A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...
with its apex
Apex (mollusc)
Apex is an anatomical term for the tip of the mollusc shell of a gastropod, scaphopod, or cephalopod mollusc.-Gastropods:The word "apex" is most often used to mean the tip of the spire of the shell of a gastropod...
nipple-shaped. The size of the shell varies between 1 mm and 8 mm. The whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...
are generally convex-shaped with a distinct suture. The aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....
is ovate, roundish or pear-shaped with its anterior end rounded, the posterior end acute and with the peristome
Peristome
The word peristome is derived from the Greek peri, meaning 'around' or 'about', and stoma, 'mouth'. It is a term used to describe various anatomical features that surround an opening to an organ or structure. The term is used in plants and invertebrate animals, such as in describing the shells of...
complete. The thin and horny operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...
is spirally marked and equally ovate, roundish or pear-shaped.
Habitat
This species can be found on brown algae (genus FucusFucus
Fucus is a genus of brown algae found in the intertidal zones of rocky seashores almost throughout the world.-Description and life cycle:...
), in clefts of rocks, on stones, on mud or sand. Most will be found on sandy beaches along the line of the last tide.
Species
Species within the genus Rissoa include:- Rissoa aartseniRissoa aartseniRissoa aartseni is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Verduin, 1985 - Rissoa albugoRissoa albugoRissoa albugo is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Watson, 1873 - Rissoa alleryiRissoa alleryiRissoa alleryi is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Nordsieck, 1972) - Rissoa angustiorRissoa angustiorRissoa angustior is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Monterosato, 1917) - Rissoa atomus E. A. Smith, 1890
- Rissoa auriformisRissoa auriformisRissoa auriformis is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Pallary, 1904 - Rissoa auriscalpiumRissoa auriscalpiumRissoa auriscalpium, common name the golden-capped risso, is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Linnaeus, 1758) - Rissoa curta Dall, 1927
- Rissoa decorataRissoa decorataRissoa decorata is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Philippi, 1846 - Rissoa euxinicaRissoa euxinicaRissoa euxinica is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Milaschevich, 1909 - Rissoa frauenfeldianaRissoa frauenfeldianaRissoa frauenfeldiana is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Brusina, 1868 - Rissoa gemmulaRissoa gemmulaRissoa gemmula is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Fischer P. in de Folin, 1869 - Rissoa gomericaRissoa gomericaRissoa gomerica is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Nordsieck & Talavera, 1979) - Rissoa guerinii Récluz, 1843
- Rissoa guerneiRissoa guerneiRissoa guernei is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Dautzenberg, 1889 - Rissoa interruptaRissoa interruptaRissoa interrupta is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(J. Adams, 1800) - Rissoa italiensisRissoa italiensisRissoa italiensis is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Verduin, 1985 - Rissoa janusiRissoa janusiRissoa janusi is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Nordsieck, 1972) - Rissoa liaRissoa liaRissoa lia is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Monterosato, 1884) - Rissoa lilacina Récluz, 1843
- Rissoa membranacea (Adams J., 1800)
- Rissoa mirabilisRissoa mirabilisRissoa mirabilis is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Manzoni, 1868 - Rissoa monodontaRissoa monodontaRissoa monodonta is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Philippi, 1836 - Rissoa multicinctaRissoa multicinctaRissoa multicincta is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Smriglio & Mariottini, 1995) - Rissoa multicostataRissoa multicostataRissoa multicostata is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Nordsieck & Talavera, 1979) - Rissoa ordinaria E. A. Smith, 1890
- Rissoa panhormensisRissoa panhormensisRissoa panhormensis is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Verduin, 1985 - Rissoa paradoxaRissoa paradoxaRissoa paradoxa is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Monterosato, 1884) - Rissoa parva (da Costa, 1778)
- Rissoa pompholyx Dall, 1927
- Rissoa poriferaRissoa poriferaRissoa porifera is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Lovén, 1843) - Rissoa pseudogueriniRissoa pseudogueriniRissoa pseudoguerini is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Nordsieck & Talavera, 1979) - Rissoa rodhensis Verduin, 1985
- Rissoa rufilabrum Alder
- Rissoa sarsiiRissoa sarsiiRissoa sarsii is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Lovén, 1846 - Rissoa scurraRissoa scurraRissoa scurra is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Monterosato, 1917) - Rissoa similisRissoa similisRissoa similis is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Scacchi, 1836 - Rissoa splendidaRissoa splendidaRissoa splendida is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Eichwald, 1830 - Rissoa torquillaRissoa torquillaRissoa torquilla is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Pallary, 1912 - Rissoa variabilisRissoa variabilisRissoa variabilis, common name the variable risso, is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Von Mühlfeldt, 1824) - Rissoa ventricosaRissoa ventricosaRissoa ventricosa is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Desmarest, 1814 - Rissoa verdensisRissoa verdensisRissoa verdensis is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Rolán & Oliveira, 2008 - Rissoa vicinaRissoa vicinaRissoa vicina is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Milaschevich, 1909 - Rissoa violaceaRissoa violaceaRissoa violacea, common name the violet risso, is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
Desmarest, 1814
Species brought into synonymy :
- Rissoa albella Lovén, 1846 : synonym of Pusillina sarsii (Lovén, 1846)
- Rissoa albella Alder, 1844 : synonym of Rissoella diaphana (Alder, 1848)
- Rissoa alifera Thiele, 1925 : synonym of Hoplopteron alifera (Thiele, 1925)
- Rissoa basispiralis Grant-Mackie & Chapman-Smith, 1971 † a: synonym of Diala semistriataDiala semistriataDiala semistriata is a species of sea snail, a marine gastropod mollusk in the family Dialidae.-Distribution:This species is distributed in the Indian Ocean along South Africa, Aldabra Atoll and Madagascar, in the Western Pacific Ocean, in the Red Sea and in the Mediterranean Sea.- Further reading...
(Philippi, 1849) - Rissoa boscii (Payraudeau, 1826) : synonym of Melanella polita (Linnaeus, 1758)
- Rissoa calathus Forbes & Hanley, 1850 : synonym of Alvania beaniiAlvania beaniiAlvania beanii is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae.-Distribution:This species is distributed in European waters, from the North Coast of Norway and the North East Atlantic Ocean down to the Canary Islands. It can also be found in the...
(Hanley in Thorpe, 1844) - Rissoa cerithinum Philippi, 1849 : synonym of Cerithidium cerithinumCerithidium cerithinumCerithidium cerithinum is a species of sea snail, a marine gastropod mollusk in the family Cerithiidae.-Distribution:This species is distributed in the Red Sea and in the Indian Ocean along Madagascar.-References:...
(Philippi, 1849) - Rissoa coronata Scacchi, 1844 : synonym of Opalia hellenica (Forbes, 1844)
- Rissoa costata (J. Adams, 1796) : synonym of Manzonia crassa (Kanmacher, 1798)
- Rissoa costulata Alder, 1844 : synonym of Rissoa guerinii Récluz, 1843
- Rissoa crassicostata C. B. Adams, 1845 : synonym of Opalia hotessieriana (d’Orbigny, 1842)
- Rissoa diaphana Alder, 1848 : synonym of Rissoella diaphana (Alder, 1848)
- Rissoa eulimoides (C.B. Adams, 1850) : synonym of Melanella eulimoides (C. B. Adams, 1850)
- Rissoa finckhi Hedley, 1899 : synonym of Chrystella finckhi (Hedley, 1899)
- Rissoa gracilis Pease, 1860 : synonym of Pyramidelloides angustus (Hedley, 1898)
- Rissoa inconspicua Alder, 1844 : synonym of Pusillina inconspicua (Alder, 1844)
- Rissoa infrequens C. B. Adams, 1852 : synonym of Opalia infrequens (C. B. Adams, 1852)
- Rissoa integella Hedley, 1904 : synonym of Attenuata integella (Hedley, 1904)
- Rissoa labiosa (Montagu, 1803): synonym of Rissoa membranacea (J. Adams, 1800)
- Rissoa lineolata Michaud, 1830 : synonym of Pusillina lineolata (Michaud, 1832)
- Rissoa punctatostriata Tenison Woods, 1879 : synonym of Leucotina casta (A. Adams, 1853)
- Rissoa rufilabris Alder, 1844 : synonym of Rissoa lilacina Récluz, 1843
- Rissoa semistriata Philippi, 1849 : synonym of Diala semistriataDiala semistriataDiala semistriata is a species of sea snail, a marine gastropod mollusk in the family Dialidae.-Distribution:This species is distributed in the Indian Ocean along South Africa, Aldabra Atoll and Madagascar, in the Western Pacific Ocean, in the Red Sea and in the Mediterranean Sea.- Further reading...
(Philippi, 1849) - Rissoa sinuosa Scacchi, 1836 : synonym of Melanella sinuosa (Scacchi, 1836)
- Rissoa striata (J. Adams, 1797): synonym of Onoba semicostata (Montagu, 1803)
- Rissoa subangulata C.B. Adams, 1850 : synonym of Schwartziella bryereaSchwartziella bryereaSchwartziella bryerea is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae.-Distribution:...
(Montagu, 1803) - Rissoa subcostulata Schwartz, 1864 : synonym of Rissoa guerinii Récluz, 1843
- Rissoa syngenes (A. E. Verril, 1884) : synonym of Alvania syngenes (A. E. Verrill, 1884)
- Rissoa xanthias Watson, 1886 : synonym of Benthonellania xanthiasBenthonellania xanthiasBenthonellania xanthias is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae....
(Watson, 1886)