Striped anemone

Anthothoe chilensis (Lesson, 1830) is a sea anemone in the family Sagartiidae, accepted as a valid species in the World Register of Marine Species ^[1]. It is the anemone with the most references in the Peruvian literature (37) and occurs in almost every coastal region of the country ^[2].

The authors who reviewed the anemones of Peru write the species name in full, with its author, so as not to confuse it with Actinostola chilensis. They also warn that many anemones are logged only as Cnidaria or unidentified Actiniaria, which may have caused under-reporting or misidentification, and that doubts about cryptic species exist in the group ^[2].

In Peru it has been recorded in almost all coastal regions. Shallow observations from Ancash, Lima, Moquegua and Ica place it from the intertidal down to about 15 m depth, and the authors list tidepools, crevices and exposed areas as common shallow habitats ^[2].

The authors of a Peruvian study describe it as a common anemone of the rocky intertidal and subtidal on the coasts of Peru, Chile and Argentina ^[3]. In Argentina, a population in Mar del Plata harbour, at 2-3 m depth, formed dense patches throughout the year ^[4].

In the only Peruvian study of its venom, 78 specimens were collected off Lima and only the tentacles were processed. The filtrate held 1.8 mg of protein per mL, with proteins of 14 to 94 kDa, and showed haemolytic, phospholipase and proteolytic activity ^[3].

In three anemones from the rocky intertidal of Mar del Plata, Argentina, this species among them, mycosporine-like amino acids were measured, compounds linked to protection from light. All three species studied, including Anthothoe chilensis, had a high proportion of mycosporine-taurine ^[5].

At Mar del Plata, Argentina, its population hosted 54 macrobenthic taxa, mostly crustaceans, with amphipods the most abundant group, and its lowest density was 91.5 individuals per 100 cm² in spring. It coexisted at low density with the anemone Tricnidactis errans ^[4].

In a laboratory assay with larvae of the bryozoan Bugulina flabellata, undiluted exudate of Anthothoe chilensis strongly reduced settlement, while dilutions of 70% and 50% did not differ from the control. The authors read this as a chemical defence that may influence recruitment and competition ^[6].

A Peruvian review, relying on an earlier study, reports that under thermal stress it raises its rate of detachment from the substrate and appears less heat resistant than the anemone Anemonia alicemartinae; its authors suggest it may tolerate El Niño events worse, but warn that long-term data are needed ^[2].

Not medical advice. For a sting, a poisoning or an allergy, seek medical care.

The Peruvian authors who studied its venom describe it as dangerous and toxic, because it can cause skin reactions that call for care in sensitive people; they state this in the introduction, without presenting clinical cases of their own ^[3].

In the laboratory, venom fractions lysed human erythrocytes, and fraction I reached 50% haemolysis in under 5 minutes. In the assay with embryos of the sea urchin Tetrapigus niger, fraction II at 1.0 µg/mL caused 75.52% mortality in the earliest stages ^[3].

Two phospholipases A2 of about 14 kDa, purified from this anemone, produced dose-dependent oedema in the paw and skin of rats ^[7].

The species is of interest as a source of bioactive molecules: its phospholipases have been purified and characterised ^[7]. Its exudate, tested against bryozoan larvae, is being studied as a possible natural alternative to antifouling paints, although it still needs chemical characterisation and a toxicity assessment ^[6].

According to the review of Peruvian anemones, it has been recorded in tidepools, crevices and exposed areas of the intertidal, with one record from vertical walls at Guañape Island (0-5 m), and down to about 15 m depth ^[2]. These data describe where it has been recorded, not where it is easy to see; in the 2007 study it was collected off Lima, at Cabinza-San Lorenzo island, at 6 to 8 m depth ^[3].