“We want to show people the beauty of these animals, because we can’t expect people to care about something they know nothing about.”
When taxonomist Keider Neves stepped foot on the Pisces VI class submarine in November 2023, a sense of excitement and trepidation greeted him: “It was the first time I’ve been on a submarine. It was part of our training so we only went to 30 metres depth, but it was amazing.”
Neves is part of the team of researchers participating in the Ocean Census Macaronesia Tenerife Submersible and Diver Expedition. Onboard the Pisces submersible, he will descend to depths of up to 300 metres in the Radazul area. With the aid of the submersible’s robotic arm, collection devices and instruments, and a collection basket, he and his fellow aquanauts will gather samples of marine organisms, rocks, and sediment. “This is an opportunity to go way deeper, to see a world that few people have ever seen and make new discoveries,” says Neves. With any luck, those discoveries will include new species of decapods and stomatopods.
Diverse Groups with Diverse Roles
Decapods and stomatopods are two groups of marine crustaceans. Decapods are characterised by having ten feet. “They include the shrimps, lobsters, and crabs that we commonly eat,” explains Neves. Stomatopods, commonly known as mantis shrimp, are closely related to decapods. “They’re fascinating creatures,” says Neves. “They have these amazing eyes and raptorial appendages [forelegs] that they use to catch prey and fight.” Researchers estimate there are some 15,000 species of decapods and 520 species of mantis shrimp in the world. “These species play very important roles in marine ecosystems,” says Neves. Among those roles is a “link between the lower and higher levels of the food chain.” In the Antarctic, for example, krill, which are decapods, feed on phytoplankton, which sits at the bottom of the food chain. The krill are then eaten by species higher up the food chain, such as fish, whales, and seabirds. Other roles include helping to maintain ecosystems. For example, in kelp forests and algal turfs, decapods that feed on herbivores prevent overgrazing, keeping the habitat in good condition. By burrowing into soft sediments in the seafloor, mantis shrimp help keep sediments filled with oxygen, ensuring other marine life that lives underground can survive.
A Passion for Taxonomy
Neves’s journey into taxonomy began during his undergraduate degree at the University of Cape Verde. “A professor from the University of Vigo in Spain and other members of his team organised a workshop on the identification of benthic organisms. At the time, I wasn’t sure which path I wanted to follow in marine biology, so I decided to go.” Once at the workshop, Neves worked with a host of different marine life – crustaceans, sponges, corals, bryozoans, and molluscs. “That’s where I found my passion,” says Neves. After finishing his undergraduate, Neves continued to develop his taxonomic skills, first on training missions in Spain and then with a master’s at the University of Vigo.
Today, Neves, who lives in Cabo Verde, does this taxonomy work in his spare time. “Unfortunately, there aren’t many positions for taxonomists, but I really love the work, so I set up a lab at home with all the equipment I need. During the evening or on my holidays, I work on describing new species when I come across them.” Over the years, Neves has helped to identify a host of known and unknown species. Those include the first record of the striped bumblebee shrimp (Gnathophyllum Americanum) in the Cabo Verde archipelago and a new species of shrimp called Periclimenaeus ramili sp. nov., also from Cabo Verde.
The Species in the Details
Neves’s focus for the Macaronesia Tenerife Submersible and Diver Expedition is on “identifying the cryptic and small species.” Alongside collecting samples, “we’ll do our best to take several pictures of them alive,” says Neves. There are two reasons why photographic live individuals are important. First, “colouration can be important for identifying some organisms because, in some groups, the colouration can be species-specific,” explains Neves. The second reason has less to do with science. “We want to show people the beauty of these animals. They are quite small, live in really cryptic environments, and in places where people can’t get to see them,” Neves explains, noting that we can’t expect people to care about something they know nothing about.
Collecting samples and photography is only part of the work. Once at the surface, Neves will gather the crustacean samples and begin his careful and detailed analysis to identify every individual. “First, we’ll preserve the specimens and then take them to the Spanish Institute of Oceanography, where we will try to identify them down to the lowest possible taxonomic level. Ideally, that would be to the species level, or the genus.” For those specimens that appear to be new species, “we’ll have more work to do,” Neves explains. “A new species is basically a hypothesis. You’re creating a hypothesis that this is a new species, so you have to build the evidence to back that up.”
“First, you have to compare every morphological detail of that specimen with previous species to make sure it hasn’t been described before,” Neves explains. This work includes making detailed drawings of the specimen, taking photographs, and writing extensive descriptions of what the specimen looks like. “You have to describe every single part of the specimen – the antennas, the eye, the carapace, the legs, the mouth parts, everything in detail.” If available, taxonomists can also use other information about the species, like the type of habitat it lives, what it feeds on, and reproductive behaviour, as well as genetic information.
The process of describing new species can span from a few years to several decades, calling for a more expedited approach to marine discovery. Central to the Ocean Census mission is the cyber-taxonomy approach, which merges traditional taxonomy with contemporary techniques such as DNA sequencing, digital imaging, and machine learning. This method creates a ‘Digital Life Form’ for each specimen, facilitating and accelerating the classification and description of species by an expanding network of global taxonomists. While the prospect of discovering new species is one of the main reasons Neves agreed to travel to the Canary Islands to participate in the expedition, there is another motivation; “If we want to protect our environment, we need to know what is out there. So many species are at risk of extinction without ever having been discovered. That’s why I want to do this work.”
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