Weedy Seadragons: A fascinating Creature Has Been Born In Captivity
On February 13th, the Birch Aquarium in La Jolla announced on their twitter that they had finally managed to hatch two brand new baby weedy sea dragons after 25 years of caring for this unique species. This success is not only a triumph for the dedicated team that has been working on this project, but for the conservation of seadragons and other tough to breed species that may threaten extinction in the years to come.
The tweet announcing the brand new baby sea dragons.
Weedy sea dragons can be found off the coast of southern Australia, and are a protected species in both Australia and Tasmania. They inhabit rocky reefs (not to be confused with coral reefs), kelp forests, and seaweed or seagrass meadows. All of these habitats occur in fairly shallow water and depend upon a specific temperature range in order to remain healthy, because of this there is a delicate balance that can all too easily be disrupted and leave organisms displaced. These habitats are particularly threatened by agricultural runoff and other toxins that may find their way into the ocean because of their close proximity to the land, and as industry increases so does the threat of increased runoff.
Despite the threats posed by their habitat, weedy sea dragons are expertly adapted to blend in with the seagrass and seaweed in which they make their home. They have a unique body that resembles a flattened tube with a narrow tubular snout, and fins that perfectly mimic the environment around them (these fins are more exaggerated in their close relative the leafy seadragon). While their bodies help them blend into their environment, there has been a trade-off as they are very poor swimmers and are almost at the complete mercy of the tides and currents which results in them being occasionally found washed up on beaches in both Australia.
Weedy seadragon in kelp. Photo credit John Turnbull via flickr.
Luckily for sea dragons, they do not need to be speedy swimmers to catch their prey as their long toothless snouts are adapted to use suction so that they may snack on small invertebrates and fish larva. This feeding strategy is similar to their close relative, the seahorse, and that is not where the similarities end. Like the male seahorses, male seadragons take on the brooding of eggs in a specialized pouch, however, sea dragons carry their eggs on their tail, not their belly. Male sea dragons are capable of brooding two clutches of eggs every breeding season, and a large portion of the offspring fall prey to anemones on the reef. Despite their breeding strategy being known, researchers have yet to pinpoint what exactly triggers sea dragon breeding, and this is one of the things that has made it so only a handful of aquariums around the world have managed to successfully breed these animals.
Adult weedy sea dragons have no known natural predators but are listed as near threatened on the IUCN Red List. Their largest threat is the destruction of their habitat by toxins originating from the surrounding land, but they are also targeted by aquarium collectors and some eastern medicinal practices. Their misguided collection for aquariums and use in alternative medicines, however, is not their only positive impact on humans, they are a popular species for divers to seek out while participating in a bit of eco-tourism.
As eco-tourism becomes more popular, it puts species like the weedy sea dragon in the spotlight and their conservation becomes a serious topic of discussion. The success of the Birch Aquarium provides a breakthrough in this discussion as researchers begin to pinpoint what triggers breeding in the weedy sea dragon species, and perhaps other hard to breed ocean species. As their habitat is further threatened by toxic runoff, a successful captive breeding program may be all that stands between these creatures and extinction, although I do hope it does not come to that in the future. No matter how grim the mind can make situations, now is a time for celebration for the researchers that have been dedicating their time to these animals and the exciting future of sea life conservation.
References:
https://www.npr.org/2020/02/14/806030113/rare-weedy-seadragons-hatch-at-california-aquarium
https://animaldiversity.org/accounts/Phyllopteryx_taeniolatus/
https://time.com/5784209/aquarium-rare-weedy-sea-dragon-breeding/
https://www.nationalgeographic.com/animals/fish/w/weedy-sea-dragon/
