Navigation Links
A tiny, toothy catfish with bulldog snout defies classification
Date:5/13/2014

PHILADELPHIA (May 13, 2014) Kryptoglanis shajii is a strange fish and the closer scientists look, the stranger it gets. This small subterranean catfish sees the light of day and human observers only rarely, when it turns up in springs, wells and flooded rice paddies in the Western Ghats mountain region of Kerala, India. It was first described as a new species in 2011.

Soon after that, John Lundberg, PhD, one of the world's leading authorities on catfishes, started taking a closer look at several specimens.

"The more we looked at the skeleton, the stranger it got," said Lundberg, emeritus curator of Ichthyology at the Academy of Natural Sciences of Drexel University and emeritus professor at Drexel in the College of Arts and Sciences. His team's study describing the detailed bone structure of Kryptoglanis is now published in the 2014 issue of the Proceedings of the Academy of Natural Sciences of Philadelphia.

"The characteristics of this animal are just so different that we have a hard time fitting it into the family tree of catfishes," said Lundberg. From the outside, Kryptoglanis does not look particularly unusual for a catfish. But when Lundberg and his colleagues looked at its bones using digital radiography and high-definition CAT scans, they found some surprises.

Kryptoglanis was missing several bony elements a characteristic fairly common for subterranean fish. But there were also changes in the shapes of certain bones, changes so strange that Lundberg described them as "completely unique among catfishes and all fishes as far as I know." Numerous individual bones were modified in the face, giving the fish a compressed front end with a jutting lower jaw like a bulldog's snout, if a bulldog also had four rows of conical, sharp-tipped teeth.

Multiple changes piled up in one part of the body could mean there is a functional purpose for those changes. "In dogs that was the result of selective breeding. In Kryptoglanis, we don't know yet what in their natural evolution would have led to this modified shape," Lundberg said. Based on its teeth and subterranean home, Lundberg said that Kryptoglanis most likely eats meat, in the form of small invertebrates and insect larvae whatever might be found in the groundwater and could be captured by the fish, which at less than ten centimeters is smaller than an adult human's pinkie finger. The fish can move swiftly in its environment, as evidenced by video footage of collected fish darting through water to grab food.

But why Kryptoglanis is so different, and what its closest relatives are, remains a mystery.

Lundberg's team wasn't alone in asking the question. Lundberg's team examined three specimens of Kryptoglanis using digital radiography, and one of these specimens using high-resolution X-ray computed tomography resulting in detailed, three-dimensional CAT scan images after careful preparation and analysis by Lundberg's colleague and co-author, Kyle Luckenbill, interim collection manager and a research assistant at the Academy. (A video visualization of the fish's internal bony structures is available at http://youtu.be/PBqndwVdnrc.)

At the same time, a separate team led by Ralf Britz at the Natural History Museum of London independently examined the bone structure of Kryptoglanis using a technique of visualizing the skeleton called clearing and staining a chemical method in which the fish's soft tissues are rendered as clear as glass and bones and cartilage are stained in contrasting colors. This team's description of the structures was published in the March 2014 issue of the journal Ichthyological Exploration of Freshwaters.

"There was an amazing congruence between the results," Lundberg said. "Neither of us was way out."

Neither could figure out which other catfishes Kryptoglanis was most closely related to, although Britz's team chose to assign it to its own new taxonomic family within the order of catfishes.

This fish just one of many unresolved branches on the catfish family tree, in a section where even DNA evidence has thus far proven unhelpful. Subterranean species like Kryptoglanis tend to have dramatically different DNA sequences from one another and from their open-water relatives, making it difficult to identify their evolutionary histories.

"It continues to be a puzzle," Lundberg said.


'/>"/>

Contact: Rachel Ewing
raewing@drexel.edu
215-895-2614
Drexel University
Source:Eurekalert  

Related biology news :

1. Drivers of marine biodiversity: Tiny, freeloading clams find the key to evolutionary success
2. American College of Rheumatology releases first classification criteria for polymyalagia rheumatica
3. Study confirms prognostic value of new IASLC/ATS/ERS adenocarcinoma sub-classification
4. New classification system for cardiomyopathy
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
A tiny, toothy catfish with bulldog snout defies classification
(Date:3/11/2016)... Germany , March 11, 2016 http://www.apimages.com ... - Cross reference: Picture is available at AP Images ( http://www.apimages.com ... from DERMALOG will be used to produce the new refugee identity ... other biometric innovations, at CeBIT in Hanover ... scanner from DERMALOG will be used to produce the new refugee ...
(Date:3/10/2016)... --  Unisys Corporation (NYSE: UIS ) today announced ... testing its biometric identity solution at the Otay Mesa border ... identify certain non-U.S. citizens leaving the country. ... determine the efficiency and accuracy of using biometric technologies in ... until May 2016. --> the United States ...
(Date:3/9/2016)... Fla. , March 9, 2016  Crossmatch ... authentication and enrollment solutions, today announced the addition ... ® Altus multi-factor authentication platform. New ... InfoSec managers to step-up security where it,s needed ... Washington, DC . --> ...
Breaking Biology News(10 mins):
(Date:4/27/2016)... VANCOUVER, British Columbia , April 27, 2016 ... "Gesellschaft" oder "NanoStruck") (CSE: NSK) (OTCPink: NSKQB) ( ... sie im Anschluss an ihre Pressemitteilung vom 13. ... Inc. erhalten hat, ihre Finanzen um zusätzliche 200.000.000 ... auf 4.000.000 Kanadische Dollar zu bringen. Davon wurden ...
(Date:4/27/2016)... ... April 27, 2016 , ... PathSensors, Inc., a leading environmental ... Lamka will assist PathSensors in expanding the use of the company’s CANARY® technology ... test platform for the detection of harmful pathogens, including a number of bacteria, ...
(Date:4/27/2016)... MedDay, a biotechnology company focused on the treatment of ... as Chairman of its Board of Directors. Catherine ... who contributed to the rapid development of the Company since ... her career in strategy consulting and investment banking in ...  She held C-Suite level roles in some of ...
(Date:4/26/2016)... ... 2016 , ... The European Patent Office (EPO) today announced that ... for the European Inventor Award 2016 in the category "Non-European countries." The winners of ... ceremony in Lisbon on June 9th. , The human capacity to walk with fluidity ...
Breaking Biology Technology: