Five New Species of Deep Sea Squat Lobsters Has Been Found and Needs Revision for Its Classification

Using molecular data and microCT, they discovered a wider species distribution range and shallower genetic diversity, implying that the current classification of squat lobsters should be revised.

Discovery of Five New Deep-Sea Squat Lobster Species

(Photo : David Baker/Unsplash)

Munidopsid squat lobsters (family Munidopsidae) are among the most abundant decapods found at the ocean's deepest depths, as per ScienceDaily.

They are the most diverse group of squat lobsters in the East Pacific and live in one of the harshest ocean environments.

Squat lobsters are related to hermit crabs rather than well-known lobsters or crabs because of the folding of the tail (or abdomen) beneath the body.

Squat lobsters are found in over 1,000 different species, ranging from cold Antarctic waters to tropical areas in the Indian, Atlantic, and Pacific Oceans.

Their diversity is most noticeable in the West Pacific tropics.

Every year, dozens of new species of deep-sea squat lobsters are described.

However, the true diversity of these animals is unknown because current classification has historically relied on the morphology, or character traits, of these animals.

Researchers from Harvard University's Department of Organismic and Evolutionary Biology (OEB) described five new deep-sea squat lobster species in a new study published in Invertebrate Systematics.

Using molecular data and microCT, they discovered a wider species distribution range and shallower genetic diversity, implying that the current classification of squat lobsters should be revised.

During a visit to the Scripps Institution of Oceanography last year, Paula Rodriguez Flores, a taxonomist, discovered the fourth and fifth species in the Benthic Invertebrate collection.

The fifth species was unexpected. The specimen was discovered but it was not recognized as unique until Rodriguez Flores examined it closely.

"It was thrilling to discover three new species in the MCZ collections and the other two at Scripps," Rodriguez Flores said.

"This group is one of the few decapod crustaceans that live at such depths where they are abundant; there is a vertical distribution limit for these decapods where you don't find any more at certain depths, which makes these animals very interesting."

Flores was visiting various museum collections to gather material for a study of the taxonomy and systematics of this group found in various locations.

She investigated these animals' genetics using a molecular approach.

According to Rodriguez Flores and Senior author OEB Professor Gonzalo Giribet, Curator of Invertebrate Zoology and Director of the MCZ, the specimens were very evolutionary divergent, based on the genetic data.

The scientists reconstructed the phylogeny of about 170 specimens from the Pacific, Atlantic, and Indian oceans.

Rodriguez Flores discovered a general pattern in which specimens living below 1000 meters have shorter genetic distances and a wider geographic distribution range.

Especially when compared to related species that live at depths of 400 meters or less,

The reconstruction revealed that the current systematics of squat lobsters needed to be revised.

Approximately one million species are threatened with extinction, with 40% of all species facing extinction by the year 2100.

The deep sea covers more than 70% of the Earth's surface.

Previously thought to be a vast homogeneous environment, scientists have discovered regional biodiversity and endemism (limited to a small geographical area) in abyssal species that were previously thought to be widely distributed based on traditional morphology.

Also Read: Consequence of Climate Change: Baby Lobsters Cannot Survive in Warmer Waters

Are squat lobsters really lobsters?

Squat lobsters are classified as Arthropoda. They are mostly found in deeper waters and have claws that can be twice as long as their bodies, as per NOAA.

They have long, waving, whip-like antennae that they use to locate objects and, more importantly, to maintain individual distance - the space between one squat lobster and another.

Squat lobsters typically feed on small marine worms or crustaceans, or they scavenge on dead animals.

Squat lobsters, the dominant decapod (crustaceans with ten feet) on Lophelia coral banks in the Gulf of Mexico, are frequently seen with their claws raised high above the plane of the reef, which could be an important feeding posture.

Some squat lobster species that live among larger corals or feather stars will steal and eat some of the protective slimes from a coral, but they will spread their pincers to warn off intruders on "their" coral.