Tectura persona (Rathke, 1833)
Common name(s): Mask Limpet, Masked limpet, Speckled limpet, Large variegated limpet, Inflated limpet
|Synonyms: Notoacmea persona, Acmaea persona|
|Tectura persona crawling along a rock in the upper midlittoral at night on Sares Head|
|(Photo by: Dave Cowles, Sept 2005)|
How to Distinguish from Similar Species: This is the only large, inflated limpet found in the upper midlittoral zone. Tectura scutum looks very similar but it is much flatter, with a height not more than 1/3 the width.
Geographical Range: Aleutian Islands to Isla Socorro, Mexico; less common south of Monterey Bay, CA
Depth Range: Upper midlittoral
Habitat: Underside of rocks and ledges during the day, more wide-ranging at night
Biology/Natural History: This large, common intertidal species is negatively phototactic, so they are usually in crevices or on the underside of boulders during the day. It is commonly found on the roofs of sea caves. They come out to feed at night. It is one of the largest limpets that can be found in the intertidal here in the Pacific Northwest (though it does not get as large as the owl limpet, Lottia gigantea, which is found further south). The white spots on the shell are translucent, and may be used to help the animal avoid bright light. The gut of this species often has a large parasitic protozoan, Eupoterian pernix. This species can be found in brackish water. Predators include black oystercatchers, which capture many of them in the Rosario area, and crows, which may explain why they usually retreat to high up on vertical surfaces or under overhangs, in shaded places during the day. They are most common in the upper midlittoral so seastars and oyster drill snails are less likely to be a problem for them. They do not show an escape response to sea stars, as do some lower-living limpets such as the keyhole limpet Diodora aspera. In California, spawning is in March and April.
The "persona" in the name refers to the dark stain on the interior of the apex, which sometimes looks like a mask or a person's face.
|Main Page||Alphabetic Index||Systematic Index||Glossary|
Brusca and Brusca, 1978 (as Notoacmea persona)
Carefoot, 1977 (As Notoacmea persona)
Johnson and Snook, 1955 (as Acmaea persona)
McConnaughey and McConnaughey, 1985 (as Notoacmea persona)
Morris, 1966 (as Acmaea persona)
O'Clair and O'Clair, 1998
Ricketts et al., 1985 (as Notoacmea persona)
Bullock, T.H., 1953. Predator recognition and escape responses of some intertidal gastropods in the presence of starfish. Behavior 5: 130-140
A student study at Rosario by Pick and Reiswig (2007) found that the
black oystercatchers Haematopus bachmani nesting on Northwest Island
are being selective in the limpets they capture. Although Lottia
digitalis was the most common limpet found in intertidal transects
on Northwest Island and were the species found at the highest tide levels
so they should have been more available than any other species, they were
not the most abundant in shell middens found near the oystercatcher nesting
and feeding site. The oystercatchers selected Lottia digitalis
less often than expected, and those they did select were near the maximum
size range found in the intertidal. The oystercatchers seemed to
prefer other, larger limpet species such as Tectura persona, Tectura
scutum, and Lottia pelta, all of which were found by chi-squared
analysis to be in significantly higher numbers in the midden than expected
from the intertidal abundance. Whether this selection by the oystercatchers
is due to a specific selection of species or simply a selection of the
largest individuals present in the intertidal is not known.
In this view one can see the apex which inclines forward; the inflated nature of the posterior slope of the shell, and the fact that this limpet is much taller than is Tectura scutum.
Night photo by Dave Cowles, Sept 2005.
This individual was at Swirl Rocks. Total length about 3-4 cm. Photo by Dave Cowles, July 2007
The degree of development of the apical blotch and the dark marginal line can vary considerably, as seen in this assemblage of Tectura persona shells collected near a black oystercatcher nesting and feeding area.
Photo by Dave Cowles, July 2007