a large constellation (the Fish or Fishes), said to represent a pair of fish tied together by their tails.
∎ [as genitive] (Pis·ci·um
/ ˈpishēəm/ )
used with a preceding letter or numeral to designate a star in this constellation:
the star Alpha Piscium.
the twelfth sign of the zodiac, which the sun enters about February 20.
∎ (a Pisces)
a person born when the sun is in this sign.
/ -sēən/ n. & adj.
(in sense 2).
In some classifications, a superclass of the Gnathostomata
(jawed chordates) comprising the fishes (compare Tetrapoda
). The whole body of a fish is covered with a tough, usually scaly, skin (see scales
), which extends over the eye and contains pigments and sometimes slime glands. The circulatory system
is a single circuit with blood passing through two sets of capillaries, one at the gills and the other in the body tissues. Three semicircular canals
are present in the inner ear. The sense of smell is particularly well developed and pressure waves are detected by the lateral-line system (see lateral-line canal
). Fossils of fish date back to the Ordovician period
, 505–438 million years ago. There are two classes of modern fish: Chondrichthyes
(cartilaginous fishes) and Osteichthyes
In older classifications, a superclass containing the four classes of fish: the two extant classes Chondrichthyes
(cartilaginous fish, e.g. sharks) and Osteichthyes
(bony fish), the extinct class Placodermi
, and also the most primitive of the vertebrates of the class Cephalaspidomorphi
. The first protofish are known from late Cambrian
fossils, and the first true fish, an agnathan, has been recorded from earliest Ordovician
sediments. Most modern classifications omit the term ’Pisces’, regarding it as artificial. See also GNATHOSTOMATA
Pisces (pī´sēz) [Lat.,=the fishes], constellation lying directly S of Andromeda and on the ecliptic (the sun's apparent path through the heavens) between Aries and Aquarius; it is one of the constellations of the zodiac. Pisces is traditionally depicted as two fishes. Because of the precession of the equinoxes, the vernal equinox has moved westward from the constellation Aries (where it was located c.2,000 years ago) into Pisces. There are no exceptionally bright stars in Pisces, but a nova was observed there in 1925. Pisces reaches its highest point in the evening sky in November.
•fasces • calces • heartsease
, amanuenses, menses, Waldenses
, exegeses, faeces (US
•radices • appendices • indices
•codices • pontifices
•helices • Ulysses • nemeses • apices
, dominatrices, matrices, testatrices
•tortrices • executrices • diaereses
•vertices • parentheses • syntheses
, Cambyses, cicatrices, crises, Pisces
, diagnoses, misdiagnoses, neuroses, prognoses, psychoses, scleroses, symbioses
•anabases • apodoses • emphases
•anamorphoses • periphrases
•thoraces • entases • protases
a large constellation (the Fish or Fishes), said to represent a pair of fishes tied together by their tails. In Astrology, the twelfth sign of the zodiac, which the sun enters about 20 February.
Pisces (the Fishes)
Inconspicuous equatorial constellation situated on the ecliptic between Aquarius and Aries; it is the 12th sign of the Zodiac.