ESF Top 10 New Species list 2017

Aquatic scientific names in the news …

A species of freshwater stingray, Potamotrygon rex, a swimming centipede Scolopendra cataracta, and a marine worm Xenoturbella churro, all feature in this year’s ESF Top 10 New Species list.

The list, an annual event established in 2008, is compiled by ESF’s International Institute for Species Exploration and comprises the Top 10 species from among the thousands of new species named during the previous year, selected by an international committee of taxonomists and calls attention to the fact that new discoveries are being made even as species are going extinct faster than they are being identified.

The list is published around May 23 each year to coincide with the birthday of Carolus Linnaeus, the father of modern taxonomy.

Potamotrygon rex Carvalho 2016

Dorsal view of juvenile specimen
Image: Marcelo R. de Carvalho

This large, strikingly patterned freshwater stingray is endemic to the Tocantins River in Brazil and is among the 35 percent of the 350 documented fish species in the Tocantins River that are found nowhere else on Earth. The type specimen is 1,110 mm in length. Large specimens may weigh up to 20 kg.

The stingray has a blackish to blackish-brown background colour, with intense yellow to orange spots that, combined with its size, earn it the title “king.” The discovery of such a large and brightly coloured ray highlights how incompletely we know fishes of the Neotropics.


Potamotrygon – Greek, Potamo-, potamos (ποταμος), river, stream; Latin, trygon, (Greek τρυγων) a stingray.

rex – Latin, absolute monarch, king – named for its large size and striking color pattern

Scolopendra cataracta Siriwut, Edgecombe & Panha, 2016 – Waterfall Centipede or Swimming Centipede

The largest reported centipede, with a maximum recorded body length of around 20 cm.
Image: Siriwut, Edgecombe and Panha

This new centipede is black, has 20 pairs of legs and is up to 20 cm in length. It is the first species of centipede ever observed to be able to plunge into water and both run along the stream bed, in much the same manner as on dry land, and swim with eel-like horizontal undulations of its body. It would appear to have a hydrophobic surface as out of water, water rolls off the centipede’s body leaving it totally dry.

The species, with its surprisingly adept swimming and diving abilities, was discovered under a rock but escaped into a stream where it rapidly ran to and hid under a submerged rock. A member of the predominant centipede genus in tropical regions, the centipede’s amphibious ability is unprecedented. Its population status is of concern because of habitat destruction, including tourist activities, along streams and river embankments where the new species is found.


Scolopendra – Latin, (Greek σκολοπενδρα), a kind of multipede, millepede.

cataracta – Latin, a waterfall. Named for the Tad E-tu Waterfall where the type was collected

Xenoturbella churro Rouse, Wilson, Carvajal & Vrijenhoek, 2016

Discovered deep in the Gulf of California, 1,722 meters below the surface, Xenoturbella churro is a 10 cm-long marine worm, one of half a dozen species now known in the genus. It is representative of a group of primitive worm-like animals that are the earliest branch in the family tree of bilaterally symmetrical animals, including insects and humans. Like some of its relatives it’s believed to feed upon mollusks, such as clams. Curiously, much like coelenterates (corals, anemones, etc.) they have a mouth, but no anus.

Dorsal view. Image: Greg Rouse


XenoturbellaGreek, Xeno-, xenos (ξενος), a guest, stranger, foreigner; foreign, strange; Latin turbella a little crowd, a bustle, stir, diminutive of turba crowd – referring to the cilia which produce minute whirls in the water.

churro – Spanish, a type of fried pastry. The new species is uniformly orange-pink in color with four deep longitudinal furrows that reminded the authors of a churro, a fried-dough pastry popular in Spain and Latin America.

See also: ESF Top 10 New Species list 2016

The Vaquita

Aquatic scientific names in the news …

17th May 2017

The Vaquita

The rarest marine mammal in the world, Phocoena sinus, the Vaquita is in grave danger of extinction as a result of illegal fishing.

Vaquita. Image: Paula Olson (NOAA)

The Vaquita, a 1.4 metre long porpoise, is in danger as a side effect of the illegal trade in Totoabo swim bladders driven by the Chinese black market. The swim bladders are considered a delicacy in Chinese cuisine and are believed by many Chinese to be a treatment for fertility, circulatory, and skin problems. Although those from domestic waters are preferred these are now exceedingly rare having been intensively fished for decades. This has driven a highly lucrative illegal trade in Vaquita fishing to the Gulf of Mexico with the bladders commanding an average price of $20,000 per kilogram making them a more valuable commodity than cocaine or elephant ivory.

The Totoabo, Totoaba macdonaldi, is the largest member of the drum family Sciaenidae, it grows up to two metres in length and is itself a rare endangered species; formerly an abundant species it has been subject to intensive fishing, subsequently commercial fishery was banned in 1975.

Totoaba. Image: FOA

It is believed that there may be as few as 30 Vaquita left in the northern Gulf of Mexico and that they could become extinct within months. The population has been largely eradicated as by-catch of the illegal Totoaba fishing.

The fish, along with the porpoises, are captured in gill-nets, currently banned by the Mexican government. This ban expires at the end of May and on Tuesday the conservation group WWF called on Mexico to introduce and enforce a permanent ban on all gill-nets saying, “The last hope for the species is the Mexican government immediately putting in place and properly enforcing a permanent ban.”

With extinction looming an emergency plan is being put in place to try to round up a few individuals and place them in a sanctuary, the success of the plan is uncertain as the capture and relocation of Vaquita has not been previously attempted.

The common name vaquita comes from Spanish meaning little cow.


Phocoena sinus Norris & McFarland, 1958, the Vaquita.

Phocoena – Greek, phokaina (φωκαινα), porpoise.

sinus – Latin, a bay, bight, gulf. “The specific name sinus was suggested to Norris and McFarland by Carl L. Hubbs and is Latin, meaning bay, referring to the occurrence of the species in the Gulf of California.”

Ref. RL Brownell Jr. 1983 Mammalian Species, No. 198, Phocoena sinus. The American Society of Mammalogists

Totoaba macdonaldi  (Gilbert, 1890), the Totoaba.

Totoaba – Eytmology unknown. Name likely of native American origin.

macdonaldi – Latinized surname. Likely honouring US fisheries scientist Marshall McDonald, (1835 – 1895), commissioner of the United States Commission of Fish and Fisheries (1888-1895).

Land crab migration

Aquatic scientific names in the news …

3rd May 2017

Land crab migration

It’s that time of the year when land crab migrations tend to be in the news. The most recent reports are on the migration of red, yellow, and black land crabs in Cuba marching from the inland forests down to the sea at the Bay of Pigs. The species of land crabs involved in the Cuban migration is Gecarcinus ruricola.

Image: P.Lindgren

After the first spring rains millions of female crabs migrate to the sea to spawn before returning to their burrows in the forests. In around 20 days the reverse will happen with millions of crab larvae emerging from the sea and migrating to the forests to spend the rest of their lives on land.

Image: Jonathan Wilkins

The land crab breeding migration is an annual event but varies in timing and intensity from year to year. It usually starts anytime from mid April to mid May and can last for up to 3 months, sometimes with a peak in mid May, sometimes with no obvious peak in activity. The migrations show some correlation with moon phase but are more strongly influenced by rainfall, though not in any consistent way.


Gecarcinus ruricola (Linnaeus, 1758) variously called the Purple Land Crab, Black Land Crab, or Red Land Crab

Gecarcinus – Greek, Ge-, gh (γη), earth, ground, land; carcinus, karkinos (καρκινος), crab.
ruricola – Latin, that lives in or belongs to the country, rural, rustic.

Note: the proliferation of common names owes to the existence of numerous colour morphs of this species including black, red, yellow, and green.