Humpback Whale Instigates Object Play with a Lion’s Mane Jellyfish

Cetaceans are well-known for their intelligence, charismatic nature, and curiosity. Many species, particularly odontocetes, are known to investigate and manipulate novel objects they encounter. Yet, disentangling the drivers of these behaviors and distinguishing between those that are simply playful and those which serve a specific function remains challenging due to a lack of direct observations and detailed descriptions of behaviors. This is particularly true for mysticetes such as humpback whales (Megaptera novaeangliae), as records of object use are far less common than in odontocetes. Here, we present evidence of novel object use from a first of its kind encounter between an individual humpback whale and a large lion’s mane jellyfish (Cyanea capillata) in the coastal waters off New England. We detail the interaction and discuss possible drivers for the behavior, with a focus on cetacean innovation, ectoparasite removal, and wound healing.

Lion's mane jellyfish sting

The authors present the case of an Irukandji-like syndrome resulting from cnidarian envenomation, following multiple stings from the lion's mane jellyfish (Cyanea capillata) encountered by a sea swimmer in the coastal waters of the UK. This case presents the initial features of Irukandji-like syndrome in this 45-year-old female, her management in the emergency department and subsequent discharge. Envenomation from the lion's mane species and the Irukandji syndrome are briefly discussed.

The Diversity of the Endobiotic Bacterial Communities in the Four Jellyfish Species

The associated microbiota plays an essential role in the life process of jellyfish. The endobiotic bacterial communities from four common jellyfish Phyllorhiza punctata, Cyanea capillata, Chrysaora melanaster, and Aurelia coerulea were comparatively analyzed by 16S rDNA sequencing in this study. Several 1049 OTUs were harvested from a total of 130 183 reads. Tenericutes (68.4%) and Firmicutes (82.1%) are the most abundant phyla in P. punctata and C. melanaster, whereas C. capillata and A. coerulea share the same top phylum Proteobacteria (76.9% vs. 78.3%). The classified OTUs and bacterial abundance greatly decrease from the phylum to genus level. The top 20 matched genera only account for 9.03% of the total community in P. punctata, 48.9% in C. capillata, 83.05% in C. melanaster, and 58.1% in A. coerulea, respectively. The heatmap of the top 50 genera shows that the relative abundances in A. coerulea and C. capillata are far richer than that in P. punctata and C. melanaster. Moreover, a total of 41 predictive functional categories at KEGG level 2 were identified. Our study indicates the independent diversity of the bacterial communities in the four common Scyphomedusae, which might involve in the metabolism and environmental information processing of the hosts.

Medusophagy in northern fulmars Fulmarus glacialis: feeding behaviour observed at sea

Several marine animals prey extensively on jellyfish in spite of the low energy contents of this type of prey. Northern Fulmars Fulmarus glacialis observed in the Barents Sea feeding on medusae of lion’s mane jellies Cyanea capillata fed from the underside of the jellyfish, eagerly ingesting gonadal tissue as well as oral arms and tentacles, while the gelatinous tissue of the umbrella apparently was neglected by the birds. Gonads, arms and tentacles have about five times higher energetic contents than the tissue of the bell, approaching that of some species of fish. Aggressive defence of their prey and a continued feeding on jellyfish in the presence of discarded fish offal indicated jellyfish to be more than a second choice food for Northern Fulmars. The observations clearly showed that the Fulmars did not primarily feed on organisms associated with jellyfish. Their abundance and slow swimming make jellyfish an easily available prey. Scyphozoan cnidarians may be more important to pelagic seabirds than generally thought.