A Look Back at Gulf Stream Orphan Season: Facts and Favorites

One of several conservation projects the New England Aquarium participates in is the Gulf Stream Orphan (GSO) Project, a reporting network designed to gather sightings of unusual tropical and subtropical species in the Northwest Atlantic. This past year was a booming season for sightings of these fish, pushing the total number of sightings to the GSO Project on iNaturalist to over 3,000 observations!  

The GSO Project parameters are configured to gather a wide variety of species observations from the coastal areas of the United States and Canada, including some species that may just be seasonal visitors in the Northwest Atlantic and not necessarily carried by Gulf Stream activity. Even if we remove some species that we know are not necessarily Gulf Stream-dispersed including Atlantic needlefish and striped burrfish, this past season appears to have been a remarkable one for tropical fish dispersal.  

Several species appear to have notable increases in reports, potentially beyond the underlying growth in iNaturalist activity. A few species that seem to stand out based on reporting frequency and anecdotal observations amongst those in the field include short bigeye, P. alta, and blue angelfish, H. bermudensis. 

To tackle the broad geographic distribution of Gulf Stream-dispersed species, the Aquarium works with several regional partners to gather environmental data and GSO observations. These species prefer warm tropical environments, so depending on where you are along the coast, peak GSO sightings typically occur in August and September when waters in the northwest Atlantic are warmest. As water temperatures drop, many of these reef species are non-migratory and will be unable to survive the cold winter. 

Through our sighting network—individuals outside the Aquarium who report GSO sightings—we’ll work to collect a small group of these fish to display in the tropical exhibits at the Aquarium. In 2024, we received several GSOs from network partners, including the Maria Mitchell Association, Wild Care Cape Cod, and Save the Bay’s Hamilton Family Aquarium.

Here are a few of our favorite Gulf Stream orphans from 2024!   

Short bigeye 

Save the Bay Hamilton Family Aquarium generously donated several short bigeyes (Pristigenys alta) to us here at the Aquarium. As their name suggests, they have huge eyes! They also have a beautiful orange coloration, bringing a bolt of color to wherever they are. Another interesting trait of this species is their deceptively large mouths. Feeding time is not only a treat for the fish but also for the aquarists, who enjoy watching these usually calm and mild-mannered fish zoom to the food and grab it in one massive bite! These fish are currently at the Quincy Animal Care Center, however, once they pass their exit exams with our veterinary team, they will be on display in the Blue Hole exhibit on the second floor. Be sure to stop by and say “hi” to these gorgeous, big-eyed friends, and if you’re lucky, you may even get to watch them eat! 

Red grouper 

In spring of 2024, the Maria Mitchell Association donated a red grouper (Epinephelus morio) GSO that was outgrowing their tanks. This fish was initially collected off of Nantucket in the summer of 2021 and based on its size at the time of collecting, we were able to estimate that the grouper was around three years old when it came to the Aquarium. This fish had the unique experience of riding a ferry to Cape Cod where Aquarium staff were able to pick it up to transport to our Quincy Animal Care Center for quarantine. Having cleared quarantine, this grouper can be found on exhibit in the Giant Ocean Tank! 

Blue angelfish 

The blue angelfish, Holacanthus bermudensis, is an amazing GSO that we have in our current collection. The juvenile fish was found amongst oyster cages by a local oyster farmer and brought to WildCare Cape Cod, a wildlife rehabilitator, both of which are on Cape Cod. This rehabilitator contacted the New England Aquarium to house this new GSO for the 2024 season. At only about 2.0 cm to 2.5 cm, this GSO made a splash at the Aquarium after being featured on our social media. Due to its small size, the fish has only been given smaller food items like copepods and capelin eggs. In the wild, juvenile blue angelfish feed on parasites that they pick off the bodies of larger fish, and they are extremely territorial over their cleaning stations! The species live near the bottom of the water column in areas with sponges, corals and/or rocks and can be found from North Carolina all the way to the Yucatan peninsula.  

Juvenile blue angelfish look rather similar to their close relatives the juvenile queen angelfish, Holacanthus ciliaris, and can truly only be determined by the curvature of the bars on their bodies; blue angelfish bars tend to be straighter. Adults will form breeding pairs for a season. Sometimes, the blue angelfish will interbreed with the queen angelfish, and the hybrids can display a wide range of color variations. Be sure to keep an eye out for this small yet mighty blue angelfish on exhibit in our Yawkey Coral Reef Center soon! 

Permit and yellow jack 

Two permits (Trachinotus falcatus) and one yellow jack (Caranx bartholomaei) were added to the GOT in 2024. One of the permits was collected by Aquarium staff in the fall of 2022 off the coast of Rhode Island via seine net and the other was donated by Save the Bay Hamilton Family Aquarium along with the yellow jack in the summer of 2023.  

The permit that was collected in 2022 was too small to exhibit after completing quarantine, so was held in Quincy and fed a variety of food items to encourage growth—starting with small items like brine shrimp and copepods and moving to larger food items such as krill and chopped seafood. The permit and yellow jack that were donated from Save the Bay were already at an exhibitable size as they had been collected in a previous year. All three were able to be moved to the Giant Ocean Tank in the summer of 2024.  

Snowy grouper and spotfin butterflyfish  

There were two snowy groupers, Hyporthodus niveatus, and a spotfin butterflyfish, Chaetodon ocellatus, that Save the Bay Hamilton Family Aquarium donated to us this 2024 GSO season. Both species were not on our collection list for the season, but we briefly housed them for a week in our quarantine room before sending them to the North Carolina Aquarium down on Roanoke Island.  

Snowy groupers get their name from the white spots that juveniles have—adults lose that spotting and have a more uniform brown coloration. Spotfin butterflyfish get their name from the black spot that is near the base of their dorsal fin, which looks like an eye to predators. While these specific individuals are not in our collection, you can still spot both species on exhibit at the New England Aquarium—snowy groupers are in the Giant Ocean Tank and spotfin butterflyfish are in our tropical exhibits! 

Orange filefish 

We’ve also received two Orange Filefish (Aluterus schoepfii) from Save the Bay Hamilton Family Aquarium. These fish have been with us at our Quincy Animal Care Center since October 2024. During this time, we’ve been ensuring they have everything they need to thrive and grow until they are big enough to be added to the Giant Ocean Tank. As you might expect, this includes feeding them a variety of food items—such as chopped seafood and whole krill—but it also includes target training. Target training is a form of conditioning used by aquarists for various reasons and involves encouraging animals to associate a specific object—in this case, a red rectangle—with a positive reward—food. 

While there are many reasons to target train individuals, one of the main purposes to target train these two is to ensure they get enough to eat. The Giant Ocean Tank is home to hundreds of animals from over 60 species—many of which are much quicker than our flat filefish friends! In fact, the unique shape of the filefish is great for hiding in narrow crevices or camouflaging among seaweed, but it doesn’t provide the speed needed to compete with some of the quicker, more torpedo-shaped fish in the tank. Thanks to target training, these filefish will be able to come to a designated area to be fed by an aquarist who will ensure they are offered plenty to eat. Both filefish are doing a fantastic job with their training so far and will be ready to graduate to the Giant Ocean Tank within the next year!