How does the purple acorn barnacle see?
The purple acorn barnacle (Amphibalanus amphitrite) is a crustacean in the order Sessilia. Its eyes belong to the vision type .
Measured in this species: colour. Measured colour or sharpness: a measured receptor set or acuity in this species; other dials come from relatives or group defaults. Every value below carries its evidence level and sources; nothing is typed by hand.
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What stands out
- It has one receptor class for colour, so it sees brightness but no hue.
- Its sharpest vision resolves 0.04 cycles per degree: the finest stripe pattern it can tell apart from grey.
The six dials
Evidence levels: how the tiers work. "Measured" means a value measured in this species; "Estimated" values come from a close relative or an eye-size formula.
| Dial | Value | Evidence | Sources |
|---|---|---|---|
| Colour | Colour receptors 1 receptor class: 532 nm (MWS (green)) measured in this species | Measured | [1] |
| Sharpness | Acuity 0.04 cycles per degree median of 1 relatives in class Maxillopoda: Argulus coregoni | Group default | [2] |
| Field of view | No value in the catalogue. | ||
| Sharp zones (foveas) | No value in the catalogue. | ||
| Night vision | Rods vs cones no rods (invertebrate photoreceptors) | Group default | |
| Motion (flicker fusion) | No value in the catalogue. | ||
Related animals
- Northern rock barnacle same vision type
- Horseshoe crab same vision type
- Tuatara same vision type
- Australian lungfish same vision type
- Brine shrimp same vision type
- Coelacanth same vision type
More crustaceans: all crustaceans with measured vision data.
Sources
- Porter ML. Crustacean photoreceptor lambda max compilation, Table 1-1 (dissertation, "Porter_2005" in VPOD); extracted from PDF by VPOD with tabula. github.com/VisualPhysiologyDB/visual-physiology-opsin-db
- Feller KD, Sharkey CR, McDuffee-Altekruse A, Bracken-Grissom HD, Lord NP, Porter ML, Schweikert LE 2021. Surf and turf vision: patterns and predictors of visual acuity in compound eye evolution. Arthropod Structure & Development 60:101002. doi.org/10.1016/j.asd.2020.101002
Every value cites its sources (all sources). Data: catalogue-v1, built 2026-09-29. Accuracy notes: how accurate is this?