What does a tick look like in photographs? - briefly
In photographs, a «tick» appears as a small, dark, oval‑shaped arachnid, often flattened against the host’s skin or a surface. Its body measures roughly 2–5 mm, with a hardened shield on the back and legs visible as tiny, pale protrusions.
What does a tick look like in photographs? - in detail
Ticks captured in photographic documentation exhibit a compact, oval body ranging from 2 mm to 10 mm in length, depending on species and feeding stage. The dorsal surface is covered by a hardened shield (scutum) in males and partially in females; the shield appears as a smooth, slightly glossy plate of brown, reddish‑brown, or dark gray coloration. Behind the scutum, the abdomen expands when the arthropod is engorged, displaying a balloon‑like silhouette that can increase to several times the unfed size and change to a pale, bluish or reddish hue.
Key visual elements observable in close‑up images include:
- Capitulum: the anterior mouthparts form a small, rectangular structure with visible palps and chelicerae, often darker than the surrounding cuticle.
- Legs: eight slender appendages emerge from the ventral side; each leg shows a series of segments (coxa, trochanter, femur, tibia, tarsus) that may be discernible in macro shots, with the tarsal claws appearing as tiny hooks.
- Eyes: simple ocelli appear as tiny dark dots on the lateral margins of the capitulum in some species.
- Surface texture: fine setae (hair‑like structures) create a subtly fuzzy appearance, particularly on the ventral side; in high‑resolution images these setae can be distinguished as individual filaments.
Photographic conditions influence the perceived morphology:
- Lighting: side illumination emphasizes the three‑dimensional shape of the scutum and the curvature of the abdomen; backlighting can reveal translucency in engorged specimens.
- Depth of field: a shallow focus isolates the capitulum or a single leg, while a larger aperture brings the entire body into sharp relief.
- Magnification: macro lenses (30×–100×) reveal microscopic details such as the arrangement of dorsal punctuations and the texture of the cuticle; lower magnification provides context within the host’s skin or vegetation.
Variations among developmental stages are evident:
- Larvae (seed ticks): approximately 0.5 mm, lacking a scutum, with a uniformly dark coloration and six legs.
- Nymphs: 1–3 mm, possessing a partial scutum, still six-legged, with a more pronounced segmentation.
- Adults: eight legs, fully developed scutum (males) or partially reduced scutum (females), and a markedly larger engorged abdomen in females.
The combination of size, coloration, shield presence, leg configuration, and abdominal expansion provides a reliable visual framework for identifying ticks in photographic records.