How does an enlarged tick look? - briefly
An enlarged tick is markedly larger than a normal tick, typically 5–10 mm long, with a swollen, balloon‑like abdomen that often appears reddish or darkened after a blood meal.
How does an enlarged tick look? - in detail
An enlarged tick presents a markedly swollen, oval‑shaped body that can reach up to 10 mm in length, sometimes larger depending on the species and the duration of feeding. The abdomen expands dramatically, filling most of the visible surface, while the anterior capitulum (mouthparts) remains relatively unchanged. The cuticle appears stretched and may become translucent, revealing the blood meal within.
Key visual characteristics:
- Size: Length 5–15 mm; width proportionally increased, giving a balloon‑like silhouette.
- Color: Ranges from pale gray to deep reddish‑brown; engorged individuals often display a dark, almost black hue due to hemoglobin concentration.
- Surface texture: Cuticle appears smooth but may show fine wrinkles as it stretches; the dorsal shield (scutum) remains rigid in hard‑ticked species, while soft‑ticked species lack a distinct scutum.
- Mouthparts: The hypostome and palps protrude from the front, appearing as a small, pointed apparatus; they remain visible despite abdominal expansion.
- Legs: Four pairs of legs are positioned near the anterior margin; they are relatively short compared to the enlarged body and may appear tucked against the capitulum.
- Eyes: Simple dorsal ocelli are present in some species, often obscured by the engorged abdomen.
The engorged state results from the tick’s ability to secrete anticoagulants and expand its midgut to accommodate thousands of microliters of host blood. This physiological adaptation produces the characteristic balloon‑like appearance that distinguishes a fed tick from other arthropods.