Wyville's crownjelly

Atolla wyvillei is a deep-water crown jellyfish (class Scyphozoa, order Coronatae) described by Ernst Haeckel in 1880 ^[1].

WoRMS lists it as semi-cosmopolitan, of mesopelagic and bathypelagic habitat, with medusae of about 15 to 200 mm in diameter; these are unreviewed notes from a regional database ^[1].

It produces local flashes and waves of light that travel across its surface epithelium ^[2].

The epithet wyvillei honours Sir Charles Wyville Thomson, chief scientist of HMS Challenger ^[3].

Haeckel described the species in 1880, on pages 488 and 489 of his work on the acraspedan medusae ^[1]; Bock places it among the new medusae Haeckel described following the Challenger expedition ^[3].

The medusae are described as small to medium in size, roughly 15 to 200 mm in diameter ^[1]. In a study from the northwest Atlantic, the sex of the gonads could already be told in medusae with a bell diameter of only 17 mm ^[4].

As a light-production trait, species of Atolla generally lack the isolated luminous points on the dome that Paraphyllina, Periphylla and Nausithoe have ^[2]. The names Atolla alexandri and Collaspis achillis are listed as unaccepted synonyms ^[1].

WoRMS describes it as semi-cosmopolitan and of mesopelagic and bathypelagic habitat, according to unreviewed notes ^[1]. Its distribution note runs from the Bay of Fundy to Cape Hatteras, and the holotype is listed as coming from the Antarctic Ocean ^[1].

The medusae used to study its gonads were collected in the Gulf of Mexico and at Cape Hatteras, in the northwest Atlantic ^[4].

In males, spermatogenesis takes place in follicles averaging about 366 × 254 μm, spread evenly through the gonad ^[4]. Oocytes arise in the gastrodermis, move into the mesoglea and grow to the final stage of vitellogenesis ^[4].

The largest oocytes measured 543 μm in specimens from the Gulf of Mexico and 263 μm in those from Cape Hatteras; all medusae were collected in September ^[4].

Herring and Widder compared in situ and laboratory recordings of 7 deep-sea scyphozoans, including Atolla wyvillei: in all of them the light appears as local flashes and waves travelling across the epithelium ^[2]. The first waves move at up to 60 cm/s and later ones are slower; after an intense burst the animal stops responding for a while ^[2].

The mesopelagic shrimp Notostomus robustus was observed in situ feeding on Atolla wyvillei in the northwest Atlantic ^[5].

The same paper includes notes on the shrimp's gut contents and mouthpart morphology ^[5].

The type specimen is kept at the Phyletisches Museum Jena. A study re-examined it and documented it with high-resolution imaging for the first time, and made known microscope sections of another syntype ^[3].

Contrasting those preparations with the published plates supports that Haeckel's drawings were based on meticulous histological analysis ^[3].