By Alicia Longo, Biologist – Fish & Invertebrates
It was inevitable that I learned the story of the Banggai Cardinalfish, having Dr. Alejandro Vagelli as a professor for many of my graduate courses at Rutgers-Camden! As you may have read on our blog, or if you’ve been following Dr. Vagelli’s Indonesian adventure, these fish are found only in the Banggai Archipelago of Eastern Indonesia, inhabiting shallow seagrass beds and coral reefs of sheltered bays.
Geographic distribution is limited due to direct development; Banggais lack a larval pelagic stage that allows most marine fishes to disperse on a large scale. Instead, males incubate fertilized eggs within their mouth, and following hatching within the oral cavity, juveniles are released after developing and absorbing their nutrient-providing yolksac. Newly released juveniles seek immediate, nearby refuge within the predator-deterring structures of host organisms (e.g. urchin spines, branching corals, and anemone tentacles) to protect themselves against predation. The fish is unable to live without the protection offered by the host with no effect on the host species, a relationship known as obligated commensalism. As Banggai cardinalfish do not exhibit any defense mechanisms, utilizing protection provided by urchins, corals, and anemones is essential at all life stages.
Brooding male Banggai:
As a Fish & Invertebrates biologist at Adventure Aquarium and Rutgers-Camden Master’s student advised by Dr. Vagelli, I had a unique opportunity to work with both Dr. Vagelli and Adventure Aquarium to research the relationship of the Banggai cardinalfish and its host anemones. In its natural habitats, Banggai cardinalfish have been reported living in close association (often observed in contact with the tentacles) with various species of anemone and the anemone-like Heliofungia coral, without triggering a predatory response from the hosts, typically observed as closing and capturing. Similar to the well-known behavior of anemonefishes with host anemones (i.e. clownfishes), Banggais seem to possess protection against the stinging cells of anemones as well.
By breeding Banggai cardinalfish at Adventure Aquarium, I could observe newly released juveniles interacting with the stinging tentacles of anemones, as well as older juveniles and adults. Preliminary results were very encouraging, as newly released juveniles were recorded moving in and out of the anemones’ tentacles, and often seeking refuge within the tentacles, sometimes to the point where they were unable to be seen! It was clear that the juveniles were touching the anemones’ tentacles, and further research will be conducted to help understand the physiology of this relationship.
First Banggai cardinalfish bred at Adventure Aquarium:
This research is important in the conservation of the Banggai cardinalfish, by identifying important relationships between these species, and by contributing to the captive breeding of this fish, as it has been fished to unsustainable levels due to its popularity within the marine ornamental/aquarium trade.
We are now exhibiting our captive-bred Banggai cardinalfish juveniles with host urchins and anemones at Adventure Aquarium! See them on exhibit in Zone C.