Not such a rare species, after all? Insights into Drymonema gorgo Müller 1883 (Cnidaria, Scyphozoa), a large and little-known jellyfish from Brazil

Abstract

Despite jellyfish’s ecological and socioeconomic impacts, they are still an understudied component of marine ecosystems. Even with its conspicuous size, reaching ~ 1 m in bell diameter, Drymonema gorgo has been rarely observed, with only a few occurrences in the literature, suggesting that it is not a common species. Here, we gathered historical records from literature, personal communication, and novel data from the World Wide Web (WWW) to obtain observations of D. gorgo along the Brazilian coast. A total of 63 observations from 1857 to 2022 were compiled, of which 57 were extracted from the web. Observations on this jellyfish concentrated between 22° S and 27° S, especially in the Cabo Frio region in Rio de Janeiro. They were reported throughout the year, except in August and October, with the highest concentrations in March (late summer). Based on the notable complement on information about its occurrence in the last ten years, we hypothesize that D. gorgo is probably not as rare as suggested by the near absence of previous literature records. In addition, biological associations of D. gorgo with other species were also discovered such as (1) predation on the jellyfish Aurelia sp. and Chrysaora lactea; (2) food item for the green turtle Chelonia mydas; and (3) association with fishes. This study provides evidence of the potential use of the WWW to obtain ecological data about conspicuous marine species occurrence, such as D. gorgo, helping to fill knowledge gaps and overcome difficulties in its detection using traditional methodologies.