What does a spider tick look like? - briefly
The spider tick is a tiny, oval arachnid, 3–5 mm long, reddish‑brown, bearing eight legs and a hardened dorsal shield (scutum) that covers its back.
What does a spider tick look like? - in detail
A spider tick is a small arachnid, typically 2–5 mm in length when unfed and up to 10 mm after engorgement. Its body consists of two main sections: a front capitulum that houses the mouthparts and a posterior idiosoma that contains the legs and internal organs. The dorsum of the idiosoma is covered by a smooth, leathery cuticle that may appear reddish‑brown, dark brown, or black depending on species and feeding state.
Key visual characteristics include:
- Eight legs, each about the same length, emerging from the sides of the idiosoma; legs are jointed, with a noticeable scutum (hard plate) on the dorsal surface of the female’s body.
- A pair of palps located near the mouthparts, shorter than the legs and ending in a small claw.
- A rounded or oval-shaped body outline, lacking the elongated “tick” silhouette seen in many other species.
- Distinctive eyes: two simple eyes placed on the anterior portion of the capitulum, often appearing as tiny dark spots.
- After a blood meal, the abdomen expands dramatically, taking on a balloon‑like shape; coloration may shift to a paler gray or yellowish hue.
The ventral side reveals a set of spiracular openings (respiratory pores) arranged in a linear pattern, and the anal groove runs along the posterior margin. In some species, a faint pattern of lighter speckles or a central dorsal line can be observed, but these markings are not consistent across all individuals.
Overall, the spider tick’s compact, almost spherical form, smooth cuticle, eight uniformly sized legs, and small anterior eyes distinguish it from other ixodid ticks and from true spiders.