- Saefftigen's pouch:
- a fluid-filled, muscular sac used to manipulate the copulatory bursa of
- a migratory stage between cercaria and adult of the schistosomes;
equivalent to the metacercarial stage in other digeneans.
- a form of asexual reproduction characterized by multiple mitoses and
cytokineses that form numerous daughter cells.
- a cell undergoing schizogony in which the cytokineses are not complete.
- Schuffner's dots:
- stippling present on the membrane of erythrocytes infected with some
species of Plasmodium, visible only under proper staining.
- a hardened, curved structure usually supporting a clamp.
- partially composed of sclerotin, a highly resistant and insoluble protein
of arthropods and some other invertebrates.
- the attachment organ of Cestoda.
- a dorsal plate covering the entire dorsal surface of some adult male ticks,
and the anterior dorsal surface of nymphs and females.
- secondary infection:
- damage of host tissues by one species of parasite that enables entry of
other species of pathogen.
- seed tick:
- a tick larva.
- selector apparatus:
- a collection of cells in the reproductive tract of female Acanthocephala
that forms a series of channels capable of directing immature eggs back into
the pseudocoele and passing mature eggs into the uterus.
- seminal receptacle:
- organ of female genital system used to receive and store spermatozoa.
- seminal vesicle:
- a distal expansion of vas deferens.
- serial polyembryony:
- the development of zygotes within other zygotes.
- not elevated above the substrate on any sort of stalk.
- fine external spine or hair.
- reproduction involving the fusion of male and female gametes.
- general term referring to the main body region excluding appendages.
- organ of female genital system used to receive and store sperm.
- sclerotized rods, often of complex shape, present in the cloaca of male
Nematoda and used to guide spermatozoa during copulation.
- a short, rigid external projection on the body, often used to aid
- spiracular plate:
- lateral opening of the respiratory system of some Arthropoda.
- small, non-motile transmission stage containing a single infective
organism; resistant to environmental conditions.
- a cell that produces a spore.
- an early developmental stage capable of asexual reproduction:
- in sporozoans it is usually enclosed within an oocyst; in digeneans it is
an intramolluscan stage lacking a gut.
- multiple fission of a zygote that forms large numbers of sporozoites.
- amoeboid transmission stage of Myxospora and Microspora.
- a daughter cell resulting from sporogony within an oocyst.
- the process of forming spores or sporozoites.
- the mid-ventral region.
- a column of stichocytes that surround and secrete into the esophagus of
- the region of the oral opening.
- the region of the body of Cestoda that is posterior to the neck, and is
- a type of cysticercus in which some segmentation is already evident.
- a short, sharp spine often used to aid penetration of a host.
- occurring close to, but not at, an extremity.
- a (usually) circular structure with some mechanism to grip another surface
within its margins.
- sucking disk:
- shallow depression in ventral surface of some Protozoa which aid attachment
to host; the beating of flagella lowers pressure in the disk area.
- a fusion of cell bodies but with retention of separate nuclei.
- reproductive process in some gregarines in which male and female
gametocytes partially fuse and encyst, then bud off gametes which fuse to form