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:4/5/2017)... YORK , April 5, 2017 Today ... is announcing that the server component of the HYPR ... known for providing the end-to-end security architecture that empowers ... HYPR has already secured over 15 million ... makers including manufacturers of connected home product suites and ...
(Date:3/30/2017)... The research team of The Hong Kong ... identification by adopting ground breaking 3D fingerprint minutiae recovery and matching ... and accuracy for use in identification, crime investigation, immigration control, security ... ... A research team led by ...
(Date:3/24/2017)... 24, 2017 The Controller General of Immigration from ... Abdulla Algeen have received the prestigious international IAIR Award for the ... Continue Reading ... ... Controller Abdulla Algeen (small picture on the right) have received the IAIR ...
Breaking Biology News(10 mins):
(Date:4/24/2017)... Linda, Ca (PRWEB) , ... April 24, 2017 ... ... protect proteins from thermal denaturation in a cellular milieu; however, the broad application ... a lack of simple platforms with sensitive quantitative readouts. Cell-based thermal stabilization assays ...
(Date:4/21/2017)... ... April 21, 2017 , ... The University of Connecticut, in ... to three startups through the UConn Innovation Fund. The $1.5 million UConn Innovation ... with UConn. , The UConn Innovation Fund provides investments of up to $100,000 ...
(Date:4/21/2017)... ... April 21, 2017 , ... Frederick Innovative Technology Center, Inc. ... technology-based businesses, recently earned a $77,518 grant from the Rural Maryland Council (RMC) ... FITCI is Frederick’s first incubator. A non-profit corporation, FITCI is a public-private partnership ...
(Date:4/20/2017)... ... April 20, 2017 , ... USDM Life Sciences , the leading risk ... industries, is pleased to announce Holger Braemer as Vice President of its ... based in Germany. , Braemer is an integral part of USDM’s expansion of ...
Breaking Biology Technology: