| Paddlefish |
two primitive freshwater fish, Polyodon and Pseuphurus,
that feed by seimming openmouthed to trap planktonic organisms; sometimes
exhibited in large aquariums as a curiosity |
| |
|
| Padina |
a brown seaweed shaped like a small fan attached at the pointed
end to a solid substrate |
| |
|
| Paguristes |
the scarlet hermit crab, P. cadenanti, often imported from the tropical
Atlantic for algae control in the marine aquarium |
| |
|
| Pagurus |
hermit crabs, typified by the small species, P. longicarpus, from
the temperate Atlantic; it is often added to marine aquariums as a
scavenger |
| |
|
| Palaemonetes |
glass or rock shrimps, often sold for fresh or brackish water aquariums
or as fish food |
| |
|
| Pallial line |
a scar marking the area of mantle attachment on the inside of the
shell of a bivalve mollusk; useful in identification |
| |
|
| Palythoa |
zoanthids, colonial anthozoans of which several species are collected
for the aquarium, consisting of several short polyps connected at
the base by a sheet of tissue |
|
|
| Panchax |
an outdated name for numerous species of cyprinodontoid fish now
mostly assigned to Aphyosemion and Epiplatys; the name persists in
both aquarium literature and the trade |
| |
|
| Pangasius |
large, predatory Asian catfish species, the most popular of which,
P. sutchii, is known in the aquarium trade as the "iridescent
shark" |
| |
|
| Pantodon |
the African butterflyfish, P. bucholzi, the only member of this
genus of surface-dwelling, insect-eating fish regularly seen in the
aquarium trade |
| |
|
| Paracheirodon |
the neon tetra, P. innesi, native to the middle and upper Amazon
River of South America, among the most popular species for the freshwater
community aquarium; it is closely related to the cardinal tetra, P.
axelrodi |
| |
|
| Parapod |
one of the leglike appendages of polychaete annelid worms |
| |
|
| Parasite |
an organism living on or within another organism; it provides no
benefit to its host, but often harms it |
| |
|
| Parasiticide |
any substance used to kill parasites |
| |
|
| Parasitism |
the symbiotic relationship between a parasite and its host |
| |
|
| Parrotfish |
any of the marine Family Scaridae, in which the teeth are fused
into a beak strong enough to allow them to bite off chunks of living
stony corals, from which they digest the polyps and excrete the skeletal
material as sand; seldom adaptable to the home aquarium |
| |
|
| Parthenogenesis |
the development of a new individual from an unfertilized egg |
| |
|
| Particle |
filter any device designed for removal of tiny flecks of unwanted
matter from aquarium water |
|
|
| Pathogenic |
disease producing, as of bacteria |
| |
|
| Pavona |
lettuce corals, delicate stony corals in which the polyps protrude
from a thin, leaflike skeleton; they will reproduce themselves in
the marine aquarium |
| |
|
| Pearlfish |
any of several species of Carapus, such as C. bermudensis, that
live in the digestive tract of certain star fish and sea cucumbers,
such as Actinopygna agassizi; they emerge at night to feed on small
organisms and return to the cucumber by day, causing it no apparent
harm |
| |
|
| Pectoral fin |
the most anterior of the paired appendages of a fish, homologous
to the arms of higher vertebrates |
| |
|
| Pedal disc |
the flattened base of the column of a sea anemone or other solitary
polyp; the animal uses it to attach itself to a solid surface |
| |
|
| pH |
a scale used to describe water's acidity/alkalinity |
|
|
| Photobiology |
the science of the interactions between living organisms and light |
| |
|
| Photoblepharon |
the flashlight fish, a deep-water marine species sometimes exhibited
in aquariums, possessing a light organ underneath each eye that contains
symbiotic, bioluminescent bacteria |
| |
|
| Photoperiod |
the relative exposure of an organism to daylight as a proportion
of the total 24-hour day |
| |
|
| Photoperiodicity |
exhibiting a cycle of behavior coordinated with the day-night cycle |
| |
|
| Photopigment |
a colored chemical compound, such as chlorophyll, that absorbs energy
from light |
| |
|
| Photosynthesis |
the process by which plants, some bacteria, and certain protists
absorb carbon dioxide to produce compounds for their growth, and emit
oxygen as a byproduct of this process. |
| |
|
| Photosynthesizer |
any organism capable of photosynthesis |
| |
|
| Phototaxis |
specific movement toward or away from light; in the former case
the movement is said to be positive, in the latter case, negative |
| |
|
| Phoxinus |
North American cyprinids commonly known as "dace"; they
are kept in temperate freshwater aquariums because of the bright coloration
of the breeding males |
|
|
| Phyletic |
referring to the evolutionary history of a tazon |
| |
|
| Phylogenetic |
having to do with the evolutionary history of groups of organisms |
| |
|
| Phymanthus |
shallow-water sea anemones from tropical Florida and the West Indies,
known as "flower anemones" in the aquarium trade |
| |
|
| Physogyra |
stony corals with bubblelike tentacles on the polyps; easily maintained
in minireef aquariums |
| |
|
| Phytophagus |
feeding primarily on plant matter |
| |
|
| Phytoplankton |
photosynthetic organisms swimming or suspended in the water column,
and important as the basis for aquatic food webs |
| |
|
| Picric acid |
a toxic chemical sometimes used in low concentrations as a parasiticidal
dip for freshwater or marine aquairum fish |
| |
|
| Pigmentation |
having color, or the color pattern of an organism such as a fish |
| |
|
| Pimelodus |
South American catfish, Family Pimelodidae, of rapid movement, bearing
long barbels; they are predatory |
| |
|
| Pinnate |
feather-like |
| |
|
| Pinnules |
the smallest subdivisions of the arms of branches of certain invertebrates,
or a subdivision of a leaf that is twice or more divided |
| |
|
| Pinocytosis |
Intake of liquid by a living cell through a process of engulfment |
| |
|
| Pipefish |
any member of the Family Syngnathidae with an elongate body not
holding the head at right angles to the spine; closely related to
seahorses |
| |
|
| Piscatorial |
having to do with an intrest in fish |
| |
|
| Pistia |
water lettuce, a floating neotropical flowering plant of the Arum
family often exhibited in garden ponds and large freshwater aquariums |
|
|
| Placoid |
scale thick, enamel-like epidermal structures found in elasmobranch
fish; their toothlike ornamentation gives the animal a rough, sandpaperlike
surface texture |
| |
|
| Plagiotremus |
scale- or flesh-nipping blennies that mimic harmless species in
order to get within striking range of their prey; sometimes exhibited
as aquarium curiosities |
| |
|
| Plankter |
any organism comprising the plankton |
| |
|
| Plankton |
unicellular and small multicellular organisms, both plant and animal,
suspended or swimming in the water column, forming an important food
source for numerous other organisms |
| |
|
| Planula |
the two layered, ciliated, free-swimming larval stage of many cnidarians,
including stony corals |
| |
|
| Platax |
batfish, Family Platacidae, tropical marine fish of which only one
species (P. obicularis) is commonly successful in an aquarium |
| |
|
| Plecostomus |
South American loricariid catfish with a mouth adapted for rasping
food from logs and stones; the name is often applied to any similar
fish by aquarium dealers |
| |
|
| Plectorhynchus |
sweetlips, tropical marine fish, Family Gasterinidae, with bold
brown and white coloration and unusual swimming movements; they unfortunately
seldom adapt to a diet of aquarium foods |
| |
|
| Pleopod |
a swimming leg located on the abdomen of a curstacean |
| |
|
| Plerogyra |
bubble corals, stony corals popular with minireef hobbists because
of teir unusual bulbous tentacles
Plezaura gorgonian soft corals often imported for minireef aquariums |
| |
|
| Plotosus |
marine catfish, the juveniles of which are attrectively striped
in yellow and lack and exhibit schooling behavior; they grow to become
large, aggressive, grey-colored adults |
| |
|
| Pocillopora |
large genus of small-polyped stony corals that can be readily propagated
from cuttings |
|
|
| Podochela |
a spider crab found in the Gulf of Mexico and collected for the
aquarium because it characteristically covers its carapace with living
invertebrates and algae collected from its immediate surroundings |
| |
|
| Poecilia |
type genus of Family Poecillidae, the livebearers, including such
perennial aquarium favorites as the guppy P. reticulata, and mollies
P. latipinna and P. velifera |
| |
|
| Poikilothermic |
referring to organisms lacking the ability to regulate body temperature,
and thus assuming the ambient temperature; cold-blooded |
| |
|
| Polychaete |
segmented marine worms in the annelid Class Polychaeta bearing numerous
bristles on the segments; there are some 15,000 species |
| |
|
| Polyp |
an aquatic animal, usually cylindrical in shape with a ring of tenticles
around the mouth. Once dead, polyp skeletons form the building materials
of coral reefs |
| |
|
| Polypterus |
bichirs, primitive, predatory lobe-finned fish of central Africa
that are popular for specialized aquariums |
| |
|
| Polytrophic |
having more than mode of nutrition |
| |
|
| Pomacanthus |
large marine angelfish in the Family Pomacanthidae, in which the
juveniles are colored much differently from the adults; beautiful
but demanding aquarium subjects |
| |
|
| Pop-eye |
a synonym for the pathological condition exopthalmus |
|
|
| Poriferan |
a sponge, any animal of Phylum Porifera |
| |
|
| Porites |
type genus of the large stony coral Family Poritidae: many species
are known and most are rather challenging to maintain in a marine
reef aquarium |
| |
|
| Post-orbit |
length the distance from the posterior edge of the eye to the anterior
edge of the opercle |
| |
|
| Potamogeton |
pondweeds, aquatic flowering plants of both tropical and temperate
lacustrine and fluvial habitats |
| |
|
| Potassium |
a chemical element (K) required by all living organisms |
| |
|
| Power filter |
a filter with a integral electric motor |
| |
|
| Powerhead |
a small submersible water pump, so named because the first models
were intended for installation at the top, or "head," of
the airlift on an undergravel filter, replacing the air supply system
and supposedly increasing filtration "power" |
| |
|
| ppb |
parts per billion, equivalent to micrograms per liter |
| |
|
| ppm |
parts per million, equivalent to milligrams per liter |
| |
|
| ppt |
parts per thousand, equivalent to grams per liter |
|
|
| Predatory |
descriptive of any animal that actively seeks out other living animals
and consumes them |
| |
|
| Prefilter |
any contrivance intended to protect filtration equipment from damage
by preventing the intake of oversized objects, or to protect aquarium
specimens from entrapment by filtration equipment, or both |
| |
|
| Premnas |
spine cheeked anemonefish, including the single species, P. biaculeatus
and its color varieties; all are popular with marine aquarium enthusiasts |
| |
|
| Preoperculum |
the area just anterior to the gill cover of many fish |
| |
|
| Pristella |
X-ray fish or pristella, characins from the Amazon Basin, now produced
in capitivity for the aquarium trade; long popular among hobbyists
as community fish |
|
|
| Prokaryote |
a living organism lacking a membranebound nucleus containing the
genetic material, or any other subcellular components surrounded by
a membrane and including Kingdom Monera, the bacteria |
| |
|
| Propagation |
increase in the numbers of a species by human intervention |
| |
|
| Protandrous hermaphroditism |
a condition of some species in which individuals begin life as males
and later change to females as a result of maturation or environmental
stimuli |
| |
|
| Protein |
a polymer of amino acids specifeid by one gene; the millions of
kinds of such molecules preform a variety of essential functions in
all living cells |
| |
|
| Protein skimmer |
any water purification device that removes dissolved organic and
inorganic matter from water by their sequestration on the surfaces
of air bubbles, and is so designed as to trap the viscous, greenish
brown foam that is produced in a receptacle from which it can be periodically
discarded |
| |
|
| Protein skimming |
the utilization of a protien skimmer for aquarium water purification |
| |
|
| Proteinaceous |
composed of protein |
| |
|
| Protist |
a unicellular organism |
| |
|
| Protogynous hermaphroditism |
a condition of some species in which individual begin life as females
and later change to males as a result of maturation or environmental
stimuli |
| |
|
| Protozoan |
an animal-like protist; also sometimes refers to any protist |
|
|
| Pseudanthias |
small sea basses, Family Serranidae, that form shoals dominated
by a single, distinctively colored male, and feed upon plankton in
shallow water; numerous species are imported for marine aquariums |
| |
|
| Pseudochromis |
dottybacks,small sea basses, Family Serranidae, of the Indo-Pacific
region that can be propagated in commercial quantities for the aquarium
trade; there are several species |
| |
|
| Pseudocolochirus |
sea apples, brightly colored holothurids from the INdo-{acific,
often improted for the marine reef aquarium despite their poisonous
flesh and eggs |
| |
|
| Pseudopterogoria |
sea feathers, gorgonian soft corals with the branches arranged in
a single plane, superficially resembling a bird's feather |
| |
|
| Pseudotropheus |
a cichlid of the African rift lakes, many species of which are popular
with aquarium hobbyists |
| |
|
| Ptereleotris |
torpedo gobies, Family Gobidae, sometimes impotred for maring aquariums,
although inclined to jump from the tank if disturbed |
| |
|
| Pterogorgia |
seafeathers, gorgonian soft corals with the branches arranged in
a single plane, superficially resembling a bird's feather |
| |
|
| Pterois |
lionfish, any of several species in Family Scorpaenidae that reach
an adult length of greater than 6 inches (15 cm); all have venomous
dorsal and pectoral fin spines |
| |
|
| Pterolebias |
South American fish, Family Rivulidae, that bury their eggs to protect
them from seasonal drought |
| |
|
| Pterophyllum |
South American freshwater angelfish, Family Cichlidae, including
P. scalare and its numerous varieties and forms; popular with hobbyists
for decades |
| |
|
| Pterosynchiropus |
the mandarinfish, P. splendidus, Family Callyonimidae; frequenlty
imported for the aquarium from Indo-Pacific reefs; requires tiny living
foods in order to survive |
|
|
| Puffer |
any fish of the Family Tertaodontidae, able to inflate itself by
drawing water into a specialized chamber, thus deterring many predators |
| |
|
| Pulmonate |
having lungs for breathing atmospheric oxygen |
| |
|
| Puntius |
a now-invalid name for numerous aquarium barbs, Family Cyprinidae,
including the tiger barb, correctly called Barbus tetrazona; the name
persist in the literature and among aquarium dealers |
| |
|
| Pupfish |
any of several species of Cyprinodon, Family Cypriodontidae, of
the American Southwest and Mexico, notable for the status of many
as endangered species and as inhabitants of thermal springs |
| |
|
| Pygoplites |
the regal angelfish, P. diacanthus, often improted for the aquarium,
but seldom adaptable to captive conditions |
| |
|
| Pylopagurus |
marine hermit crabs, including the trapdoor hermit, P. operculatus,
from the tropical Atlantic; a colorful species with an enlarged, white
chela that it uses to close the opening of the snail shell in which
it lives |
| |
|
| Pyramidella |
parasitic gastropods that sometimes infest giant clams and sea stars
exhibited in aquariums; usually controlled by introducing a predator,
such as the wrasse Pseudocheilinus hexataenia |
| |
|
| Pyrrhulina |
attractive characins of the Amazon Basin, Family Lebiansinidae;
they are good community fish |
