Peritonitis Inflammation of the peritoneum
Perivascular Surrounding a vessel (blood or lymph)
Petechiae Small, haemorrhagic spots
Phagocyte Cell capable of ingesting bacteria, foreign
particles and other cells
Phagocytosis Ingestion of large foreign particles
Pernicious anaemia A progressive anaemia characterised
by a decrease in numbers and variation of red blood cells
Phenotype Observable physical or biochemical characteristics of an organism
Photosensitivity Sensitivity of the skin to certain types of
light
Physostomous Fish with a connecting tube between the
swim bladder and a part of the alimentary canal
Physoclistous Having an swim bladder that is not connected
to the alimentary canal
Pigmentation Deposit of pigment, especially when abnormal or excessive
Pillar cell Fine cytoplasmic filaments situated parallel to
the collagen columns of the gills
PKX cell Earliest identifiable stage of Tetracapsuloides
bryosalmonae
Platyspondyly Flattened vertebral body with reduced
distance between the endplates
Pleomorphic The condition in which an individual
assumes a number of different forms during its life
Plerocercoid Cestode larva that develops from a procercoid and the stage often found in fish tissues
Pneumatic duct The duct joining the swim bladder and
alimentary canal of a physostomous fish
Podocytes Cells in the Bowman’s capsule in the kidney
that wrap around the capillaries of the glomerulus
Poikilocyte Irregular, malformed erythrocyte
Polychromasia Abnormal reaction of the red blood cells
in severe anaemia, whereby they have a bluish tinge
Polycystic Composed of many cysts
Polycythaemia Increase in the number of circulating red
blood cells
Posterior The hind end
Post-mortem After death, usually inferring dissection of
the body; see also necropsy
Preopercle Flat membrane bone in the gill cover of most
fish lying immediately in front of the opercula
Presporogonic The stage prior to the development of
sporogonia
Prevalence Number of cases existing per unit of population
at a given unit of time, generally represented as a percentage of the population. It is a static measure as compared
with the dynamic measure incidence
Procercoid Cestode larva that usually infects the first intermediate host. In aquatic animals, this host is usually a
crustacean
Proglottis Sexually mature segment of tapeworm
Prognathous Having a projecting lower jaw
Prognosis A forecast of the probable course and outcome
of a disease
Prolapse Falling of a structure, descent
Proliferate Increase by cell division
Prognathous Projecting lower jaw
Prosector A person with the special task of preparing a
dissection for demonstration
Proteinaceous Protein-like, resembling protein
Proteolysis The breaking down of proteins
Proximal Towards the centre
Pseudobranch The reduced first gill arch of a fish (on the
inner surface of the operculum, near the junction of the
preopercle)
Pseudomembrane False or new membrane (usually
fibrinous)
Psychrophilic Organisms having an optimal temperature
for growth at about 15
C or lower
Punctate Dotted or spotted
Pycnidium Hollow fruiting body that produces
pycnidiospores
Pyknosis Condensation of nuclear contents into a single,
densely staining irregular-mass
Pyriform Pear-shaped
Regeneration Renewal of tissue
Regression Reversion to an earlier stage of development
Resolution Restoration from acute inflammation to normal
Resorption Disappearance of tissue by absorption into
body fluids
Reticulocyte Immature red blood cell
Retrobulbar Pertaining to behind the eyeball
Rodlet cell Flask-shaped cell of uncertain identity found in
many fish tissues, e.g. gills, intestine, renal tubules
Rhabdomyoma Benign neoplasia of striated muscle
Rudimentary An imperfectly developed or formed organ
which is not functional and which may represent a normal
or abnormal situation
Runt Non-feeding fish, with negligible body fat and very
low condition factor
Rupture Burst, break
Saprophyte Organism that derives nourishment primarily
from dead and decaying organic matter
Sarcoma Malignant neoplasia whose parenchyma is composed of anaplastic cells resembling those of the supportive tissues of the body
Sclerosis Hardening of tissues
Scolex Anterior, head-like segment of a tapeworm
Scoliosis Lateral curvature of the vertebral column (spine)
Scleritis Inflammation of the sclera (the white outer wall of
the eye)
Secondary infection Infection in an animal which is
already infected by another pathogenic organism
Septic Related to or caused by sepsis
202
Glossary
Perivascular Surrounding a vessel (blood or lymph)
Petechiae Small, haemorrhagic spots
Phagocyte Cell capable of ingesting bacteria, foreign
particles and other cells
Phagocytosis Ingestion of large foreign particles
Pernicious anaemia A progressive anaemia characterised
by a decrease in numbers and variation of red blood cells
Phenotype Observable physical or biochemical characteristics of an organism
Photosensitivity Sensitivity of the skin to certain types of
light
Physostomous Fish with a connecting tube between the
swim bladder and a part of the alimentary canal
Physoclistous Having an swim bladder that is not connected
to the alimentary canal
Pigmentation Deposit of pigment, especially when abnormal or excessive
Pillar cell Fine cytoplasmic filaments situated parallel to
the collagen columns of the gills
PKX cell Earliest identifiable stage of Tetracapsuloides
bryosalmonae
Platyspondyly Flattened vertebral body with reduced
distance between the endplates
Pleomorphic The condition in which an individual
assumes a number of different forms during its life
Plerocercoid Cestode larva that develops from a procercoid and the stage often found in fish tissues
Pneumatic duct The duct joining the swim bladder and
alimentary canal of a physostomous fish
Podocytes Cells in the Bowman’s capsule in the kidney
that wrap around the capillaries of the glomerulus
Poikilocyte Irregular, malformed erythrocyte
Polychromasia Abnormal reaction of the red blood cells
in severe anaemia, whereby they have a bluish tinge
Polycystic Composed of many cysts
Polycythaemia Increase in the number of circulating red
blood cells
Posterior The hind end
Post-mortem After death, usually inferring dissection of
the body; see also necropsy
Preopercle Flat membrane bone in the gill cover of most
fish lying immediately in front of the opercula
Presporogonic The stage prior to the development of
sporogonia
Prevalence Number of cases existing per unit of population
at a given unit of time, generally represented as a percentage of the population. It is a static measure as compared
with the dynamic measure incidence
Procercoid Cestode larva that usually infects the first intermediate host. In aquatic animals, this host is usually a
crustacean
Proglottis Sexually mature segment of tapeworm
Prognathous Having a projecting lower jaw
Prognosis A forecast of the probable course and outcome
of a disease
Prolapse Falling of a structure, descent
Proliferate Increase by cell division
Prognathous Projecting lower jaw
Prosector A person with the special task of preparing a
dissection for demonstration
Proteinaceous Protein-like, resembling protein
Proteolysis The breaking down of proteins
Proximal Towards the centre
Pseudobranch The reduced first gill arch of a fish (on the
inner surface of the operculum, near the junction of the
preopercle)
Pseudomembrane False or new membrane (usually
fibrinous)
Psychrophilic Organisms having an optimal temperature
for growth at about 15
C or lower
Punctate Dotted or spotted
Pycnidium Hollow fruiting body that produces
pycnidiospores
Pyknosis Condensation of nuclear contents into a single,
densely staining irregular-mass
Pyriform Pear-shaped
Regeneration Renewal of tissue
Regression Reversion to an earlier stage of development
Resolution Restoration from acute inflammation to normal
Resorption Disappearance of tissue by absorption into
body fluids
Reticulocyte Immature red blood cell
Retrobulbar Pertaining to behind the eyeball
Rodlet cell Flask-shaped cell of uncertain identity found in
many fish tissues, e.g. gills, intestine, renal tubules
Rhabdomyoma Benign neoplasia of striated muscle
Rudimentary An imperfectly developed or formed organ
which is not functional and which may represent a normal
or abnormal situation
Runt Non-feeding fish, with negligible body fat and very
low condition factor
Rupture Burst, break
Saprophyte Organism that derives nourishment primarily
from dead and decaying organic matter
Sarcoma Malignant neoplasia whose parenchyma is composed of anaplastic cells resembling those of the supportive tissues of the body
Sclerosis Hardening of tissues
Scolex Anterior, head-like segment of a tapeworm
Scoliosis Lateral curvature of the vertebral column (spine)
Scleritis Inflammation of the sclera (the white outer wall of
the eye)
Secondary infection Infection in an animal which is
already infected by another pathogenic organism
Septic Related to or caused by sepsis
202
Glossary