GLOSSARY OF TERMS
The glossary of terms is currently incomplete. More terms will be added below as more taxon accounts are made.
aesthetascs: sensory hairs, usually somewhat inflated-cylindrical
ambulatory: not prehensile
appendix masculina: ♂ reproductive structures set on the endopod of pleopod 2. Often thin and elongate, can become very elaborate and fused to the endopod in some groups.
cephalon = head
basis: the basal-most segment after the coxae
biramous: splitting into two branches
carpus: the fourth main segment of the pereopod from the base
carposubchelate: subchelate with the palm on the carpus
chelate: prehensile with the main segment extending forward to form an immovable finger and the next segment(s) forming a thumb-like appendage, like a crab claw. In isopods this seems to only be present in Katianirids
colinear: subsquential segments continuing a straight line, not curving
coxae: the base of the pereopod, either fused into coxal plates
dactylus: the final segment of the pereopod, often tipped with claws
coxal plate: the fused, plate-like coxae fo Scuticoxiferans (= all isopods in our area besides Asellota and Microcerberideans) and many Microcerberideans
endopod: the medial segment of a biramous appendage
epimera: the lateral margins of the pereonal and pleonal tergites. In many isopods the pereonal coxae are fused to
epistome = frontal lamina
exopod: the lateral segment of a biramous appendage
flagellum: the distal portion of an antennae
frontal lamina: a large plate above the mouth that appears to be the fused sternites of the embryonic segments 3-4. Often nestled under or in between the antennae bases
ischium: the second main segment of the pereopod from the base
lateral: away from the midline, closer to the body margin
mandible: the first set of jaws, usually with an incisor (distalmost protrusion), a lacinia (middle protrusion), a row of spines, a molar (basalmost protrusion) and a palp near the base.
maxilla: the second and third sets of mouthparts in isopods
maxilliped: the fourth set of jaws in isopod. Usually has 4 main parts: a small endite, a palp of 5 or less segments, an epipod that covers the side of the mouth and a basis that covers the underneath of the mouth
medial: towards the midline, further from the body margin
merus: the third main segment of the pereopod from the base
nodulus lateralis: a senosory seta unique to Oniscidea, found in pairs on the pereon and sometimes cephalothorax. Position designated by the ratio between distance from the posterior border of the pereonite and the total length of the pereonite (b/c) and the ratio between distance from the lateral border of the pereonite and the total length of the pereonite (d/c).
oostegites: ♀ reproductive structures that hold the developing eggs and young.
peduncle: the basal region of an antennae. Also used in terms of the protopod
penes: ♂ reproductive structures derived from the coxae that sit on the posterioventral surface of the pereon
pereon: second tagmata of the body, contains (5-)7 segments. The appendages on the pereon segments are usually adapted for walking
pereonite: an individual segment of the pereon. Also spelt as pereonite
pereopod: an appendage of the pleon, divided into 6(-7) segments. Also spelt as pereiopod
pleon: the third tagmata of the body, contains up to 5 segments (often fused) and a telson. The appendages on the pleon segments are usually adapted for swimming, reproduction and respiration
pleonite: an indididual segment of the pleon.
pleopod: an appendage of the pleon, usually divided into two rami
prehensile: grasping, much like a hand
propus: the second to last segment of the pereopod from the base
proposubchelate: subchelate with the palm on the propus
protopod: the basal segme nt of the pleopods and uropods
rami: the segment(s) after a biramous appendage divide
stylet: the terminal segment of the pleopod 2 endopod of Janiroideans consisting of the fused appendix masculina and endite. Usually thin and elongate.
subchelate: prehensile with the main segment not extending forward and the next segment(s) forming an opposable appendage folding downwards, like the main digits in a human hand
sympod = protopod
tagmata: a collection of body segments in Arthropoda
unguis = claw
uniramous: not branching into two or more branches
Published: Jan 1, 2023
Edited: Feb, 1, 2023