Glossary of spider terms
Apophysis (plural apophyses): An outgrowth or process changing the general shape of a body part, particularly the appendages; often used in describing the male pedipalp → retrolateral tibial apophysis
Bidentate: Having two teeth
Branchial operculum: → operculum
Bulbus → palpal bulb
Calamistrum (plural calamistra): Modified setae (bristles) on the metatarsus of the fourth leg of spiders with a cribellum, arranged in one or more rows or in an oval shape, used to comb silk produced by the cribellum; see also Calamistrum
Caput (plural capita): → cephalic region
Cephalothorax or prosoma: One of the two main body parts (tagmata), located towards the anterior end, composed of the head (cephalic region or caput) and the thorax (thoracic region), the two regions being separated by the cervical groove; covered by the carapace and bearing the eyes, legs, pedipalps and mouthparts
Cheliceral tooth: A tooth-like extension on the margin of the cheliceral furrow
Claw → tarsal claw
Claw tuft: A dense group of hairs or bristles (setae) underneath the paired tarsal claws, usually well developed in hunting spiders
Conductor → palpal bulb
Copulatory opening: An opening in the ventral abdomen of female spiders; in entelegyne spiders, a double opening in the epigyne through which the embolus is inserted; in haplogyne spiders, a single opening through which male palpal bulb is inserted
Coxa → segments
Dorsal groove → fovea
Ecribellate → cribellum
Embolus → palpal bulb
Endite → maxilla
Entelegyne: A spider whose female has an epigyne and separate ducts leading to spermathecae for sperm storage and to the uterus for fertilization, creating a "flow-through" system; → haplogyne; see also Entelegynae
Epigastric furrow or epigastric fold: A transverse slit towards the front (anterior) of underside of the abdomen; the front pair of book lungs open at the edge of this furrow as do the genital openings (gonopores)
Epigyne or epigynum (plural epigynes): A hardened plate on the underside of the female abdomen in which the copulatory openings are located; only fully developed in mature females of entelegyne spiders; see also Epigyne
Eyes: The basic number of eyes is eight, arranged in two rows (e.g. as in Gnaphosidae); the front row are the anterior eyes, the row behind the posterior eyes; the four eyes to the edges are the lateral eyes, the four eyes in the centre the median eyes; the number of eyes, their sizes and arrangement varies widely and is characteristic of spider families → main eye, secondary eye
Fang: The final hinged part of the chelicera, normally folded down into a groove in the basal part of the chelicera; venom is injected via an opening near the tip of the fang
Femur → segments
Folium: A broad leaf-like marking along the medial line of the top of the abdomen
Fovea (also called thoracic furrow or dorsal groove): A depression or pit in the centre of the carapace of a spider marking an inward projection of the exoskeleton to which stomach muscles are attached
Genital opening → gonopore
Gnathocoxa → maxilla
Haematodocha → palpal bulb
Heart mark: A narrow marking along the top of the abdomen roughly corresponding to the location of the heart
Laterigrade: With legs directed to the side, hence appearing like and moving like a crab; → prograde
leg formula: The legs are numbered from the front from I to IV; the relative length of the legs can be represented by four numbers from the longest to the shortest; e.g. 1423 = first leg (leg I) is longest and third leg (leg III) is shortest
Main eye: One of the two anterior median eyes (AME) that have the light-detecting units (rhabdomeres) pointing towards the source; particularly enlarged in the families Salticidae and Thomisidae; → secondary eye, eyes
Mastidion (plural mastidia): A projection or bump on the chelicerae (not to be confused with teeth)
Metatarsus → segments
Operculum or branchial operculum (plural opercula): One of the plates on the ventral surface of the abdomen, just in front of the epigastric furrow, covering the book lungs, often pale, yellow or orange in colour; two pairs in Mygalomorphae, one pair in other spiders
Opisthosoma → abdomen
Palp → pedipalp
Palpal bulb (also called bulbus, palpal organ, genital bulb): The copulatory organ of the male spider, carried on the modified last segment of the pedipalp, used to transfer sperm to the female; see also Palpal bulb
- Embolus: The final part of the palpal bulb containing the end of the sperm duct, usually thin, sharp-tipped and strongly hardened (sclerotized)
- Median apophysis: A projection (apophysis) of the palpal bulb, below the conductor
- Subtegulum: A hardened part of the palpal bulb nearer its base than the tegulum
- Tegulum: The main hardened part of the palpal bulb
Patella → segments
Pluridentate: Having multiple teeth
Procurved: Used to describe a structure which is curved in such a way that the outer edges are in front of the central part; opposite recurved
Prosoma → cephalothorax
Rebordered: Having a thickened edge (i.e. border) (more rarely seen as reborded, from the French rebordé, e.g. in Levy (1984)); particularly used of the labium
Receptaculum (plural receptacula) → spermatheca
Recurved: Used to describe a structure which is curved in such a way that the outer edges are behind the central part; opposite procurved
Scopula (plural scopulae): A brush of hairs (setae); called a claw tuft when on the end of the foot (tarsus), where it improves adhesion
Scutum (plural scuta): A hardened (sclerotized) plate on the abdomen of some spiders
Secondary eye: An eye belonging to the three pairs – anterior lateral eyes (ALE), posterior median eyes (PME) and posterior lateral eyes (PLE) – that are primarily movement detectors and have the light-detecting units (rhabdomeres) pointing away from the source; → main eye, eyes
Segments or articles of the legs and pedipalps:
- Coxa (plural coxae): First leg segment, between body and trochanter; the coxa of the pedipalp is heavily modified to form the maxilla or endite
- Trochanter: Second leg segment, between coxa and femur
- Femur (plural femora): Third leg segment, between trochanter and tibia
- Patella (plural patellae): Fourth leg segment, between femur and tibia
- Tibia (plural tibiae): Fifth leg segment, between patella and metatarsus
- Metatarsus (plural metatarsi; also called basitarsus): Sixth leg segment, between tibia and tarsus; absent in the pedipalp
- Tarsus (plural tarsi; also called telotarsus): Seventh (last) leg segment, after the metatarsus
Seta (plural setae): A bristle; spiders have a variety of hair-like structures of increasing size that are referred to as hairs, bristles (setae) or spines
Sigillum (plural sigilla): A circular indentation on the outside of the spider, showing where an internal muscle is attached; particularly on the sternum in some Mygalomorphae and on the dorsum in some Araneomorphae
Sperm duct: A duct in the male palpal bulb used to store sperm
Spermatheca (plural spermathecae; also called receptulacum, receptulacum seminis): A structure in the abdomen of female spiders used to store sperm after insemination and before fertilization; see also Spermatheca
Spigot: A small pointed or cylindrical structure at the tip of a spinneret from which silk emerges
Spine: A pointed, rigid structure on body and legs, usually with a basal joint; spiders have a variety of hair-like structures of increasing size that are referred to as hairs, bristles (setae) or spines
Spinneret: An appendage borne on the abdomen, typically one of six arranged in three pairs: anterior (anterior median, AMS), median (posterior median, PMS) and posterior (posterior lateral, PLS); silk emerges from small spigots on the spinnerets; see also Spinneret
Sternum: The lower (ventral) portion of the cephalothorax
Subtegulum → palpal bulb
Tapetum (plural tapeta): A light-reflecting layer in a secondary eye making the eye appear pale
Tarsus → segments
Teeth: Pointed growths or bumps along the margins of the cheliceral furrow
Tegulum → palpal bulb
Thoracic furrow → fovea
Tibia → segments
Trachea (plural tracheae): A thin hardened internal tube, part of the respiratory system in many araneomorph spiders; opens on the underside of the abdomen via a tracheal spiracle; see Trachea § Invertebrates
Trichobothrium (plural trichobothria): A slender hair-like structure of variable length on the legs and pedipalps, arising from a special socket; used to detect air movements, including sounds; → seta, spine
Trochanter → segments
Unidentate: Having a single tooth
Some abbreviations commonly found in descriptions of spider anatomy include:
- ALE: anterior lateral eyes → eyes
- ALS: anterior lateral spinnerets → spinneret
- AME: anterior median eyes → eyes
- DTA: dorsal tegular apophysis, apophysis on the back of the tegulum
- DTiA: dorsal tibial apophysis, apophysis on the back of a tibia
- LTA: lateral tegular apophysis, apophysis on the side of the tegulum
- MOQ: median ocular quadrangle, the quadrangle formed by the four median eyes, → eyes
- PLE: posterior lateral eyes → eyes
- PLS: posterior lateral spinnerets → spinneret
- PME: posterior median eyes → eyes
- PMS: posterior median spinnerets → spinneret
- RCF: retrolateral cymbial fold, fold on the retrolateral surface of the cymbium
- RTA: retrolateral tibial apophysis, apophysis on the retrolateral surface of a tibia
- VTA: ventral tegular apophysis, apophysis on the underside of the tegulum
- VTiA: ventral tibial apophysis, apophysis on the lower surface of a tibia
- Jocqué & Dippenaar-Schoeman (2007), p. 20.
- Saaristo (2010), p. 13.
- Saaristo (2010), p. 14.
- Saaristo (2010), pp. 14–15.
- Saaristo (2010), pp. 15, 18.
- Saaristo (2010), p. 15.
- Jocqué & Dippenaar-Schoeman (2007), p. 21.
- Jocqué & Dippenaar-Schoeman (2007), p. 22.
- Saaristo (2010), p. 17.
- Foelix (2011), p. 21.
- Roberts (1995), pp. 13–14.
- Foelix (2011), pp. 17–18.
- Saaristo (2010), p. 16.
- Smith (1990).
- Jocqué & Dippenaar-Schoeman (2007), p. 23.
- Foelix (2011), pp. 102–103.
- Coddington, J.A. (1990). "Ontogeny and homology in the male palpus of orb-weaving spiders and their relatives, with comments on phylogeny (Araneoclada: Araneoidea, Deinopoidea)". Smithsonian Contributions to Zoology. 496: 1–52. Figs 5–8
- Foelix (2011), pp. 226–227.
- Saaristo (2010), pp. 18–19.
- Saaristo (2010), p. 18.
- Zakharov, Boris & Ovtsharenko, Vladimir (2015), "The covering setae of ground spiders (Araneae: Gnaphosidae)" (PDF), Arachnologische Mitteilungen 49, 49: 34–46, retrieved 2017-09-28
- Jocqué & Dippenaar-Schoeman (2007), p. 24.
- Levy, G. (1984), "The Spider Genera Singa and Hypsosinga (Araneae, Araneidae) in Israel", Zoologica Scripta, 13 (2): 121–133, doi:10.1111/j.1463-6409.1984.tb00029.x
- Foelix (2011), p. 27.
- Foelix (2011), pp. 103–104.
- Foelix (2011), pp. 84–101.
- Foelix (2011), pp. 41, 43.
- Saaristo (2010), p. 19.
- Jocqué & Dippenaar-Schoeman (2007), p. 26.
- Foelix (2011), pp. 89–92.
- Comstock, John Henry (1920) [First published 1912]. The Spider Book. Doubleday, Page & Company.
- Foelix, Rainer F. (2011). Biology of Spiders (3rd p/b ed.). Oxford University Press. ISBN 978-0-19-973482-5.
- Jocqué, R. & Dippenaar-Schoeman, A.S. (2007). Spider Families of the World (PDF) (2nd ed.). Tervuren (Belgium): Royal Museum for Central Africa. Retrieved 2019-07-04.
- Roberts, Michael J. (1995). Spiders of Britain & Northern Europe. London: HarperCollins. ISBN 978-0-00-219981-0.
- Saaristo, M.I. (2010). "Araneae". In Gerlach, J. & Marusik, Y. (eds.). Arachnida and Myriapoda of the Seychelles Islands. Manchester, UK: Siri Scientific Press. pp. 8–306. ISBN 978-0-9558636-8-4.
- Smith, A.M. (1990). Baboon spiders: Tarantulas of Africa and the Middle East. London: Fitzgerald Publishing.