Markus Friedrich

Markus Friedrich

Professor

More

Published on Jun 16, 2019

Cave beetle larva movie

To make the possible waiting period a bit more entertaining, one of the larvae decided to give us a glimpse of its roaming behavior. This is a 1st instar larva of about 2.5 mm length captured last ...

Group 6 Copy 175
Published on Jun 16, 2019

P. hirtus 1st larval instar exuvia annotated

Here it is:In case exuvia did not yet make it into your dictionary yet: As Qing pointed out correctly, you are looking at the former chitin based skin of the first instar larvae left behind after s...

Group 6 Copy 154
Published on Jun 08, 2019

Cave beetle larvae invite for a new challenge question

Hello there friends of the cave beetle!This may be pushing the limits of minimally shareworthy data bite but it sure is something you will never see in an actual publication. And it's been making m...

Group 6 Copy 265
Published on Jun 02, 2019

First sight of 16 degrees Celsius cave beetle larvae

It's been great to encounter the first 2 P. hirtus larvae on the yeast food patch just last Friday last day of May, i.e. what as the 31st. As I a was setting up the cultures following my last post,...

Group 6 Copy 270
Published on May 05, 2019

P. hirtus’ upper temperature tolerance limit revealed: 26 degrees Celsius

P. hirtus’ upper temperature tolerance limit revealed: 26 degrees CelsiusFirst off: My compliments on your patience with the seemingly endless duration of this cliffhanger. Turns out we can blame t...

Group 6 Copy 303
Published on Mar 24, 2019

2019 Cave beetle talk at Western Michigan University Kalamazoo

Hello there friends of the cave beetle! Very pleased to inform you about a "first second": The first time the cave beetle was invited back to the same institution, the fantastic Department of Biolo...

Group 6 Copy 769
Published on Mar 16, 2019

Waiting for the right temperature to answer the hot question

Hello there friends of the cave beetle,And many thanks for your contributions to and patience with the hot question: What was the highest temperature P. hirtus tolerated for 5 days in our experimen...

Group 6 Copy 258
Published on Jan 28, 2019

Raising a hot question

In light of the cold spell of a week coming up here in Detroit and the fantastic response to the recent post. It's been truly great to see that the cave beetle's fan base is going strong. So, I cha...

Group 6 Copy 415
Published on Jan 08, 2019

Ptomaphagus hirtus now at least 5 million years old

Ptomaphagus hirtus now at least 5 million years oldHello there, dear friends of the cave beetle, and happy new year... ! Writing this post, I am realizing that 2018 went by without a single update...

Group 6 Copy 402
Show more updates
You are right on the money again. Sensory appendage elongation is part of what is called the troglomorphic phenotype. The most striking aspect in the P. hirtus larvae are the long terminal cerci. Will post an annotated image this weekend (if time allows).
Jun 11, 2019
Exploring the temperature tolerance of a cave beetle
View comment
That is right indeed. Congratulations Qing and thank you for your insightful input! Turns out we are looking at a shed first larval instar cuticle or exoskeleton. This documents successful growth and development of the larvae on the 16 degrees Celsius plate. It's easy to grow in body size, but quite a challenge for any molting animal (Edysozoa) to break through the tightening grip of an outsized cuticle and leave it completely behind. So that's why this little piece of larval cuticle is a really encouraging finding.
Jun 11, 2019
Exploring the temperature tolerance of a cave beetle
View comment
Hi there Qing, Interesting guess. What exactly do you mean by "molt"?
Jun 10, 2019
Exploring the temperature tolerance of a cave beetle
View comment
Your kind words are much appreciated, Monique. The cave beetle friends will stay informed here. Promise!
May 21, 2019
Exploring the temperature tolerance of a cave beetle
View comment
Hello there Tom, and many thanks for drawing attention to Hadenoecus subterraneus (https://en.wikipedia.org/wiki/Hadenoecus), the cave beetle's food supplier. Indeed, I fully agree with that our data imply Hadenoecus subterraneus's well being as the more immediately pressing issue when it comes to the potential effects of global warming on P. hirtus.
May 07, 2019
Exploring the temperature tolerance of a cave beetle
View comment
Hello there Tom, and many thanks for drawing the attention to Hadenoecus subterraneus (https://en.wikipedia.org/wiki/Hadenoecus), the cave beetle's food supplier. Indeed, I fully agree with that our data imply Hadenoecus subterraneus's well being as the more immediately pressing issue when it comes to the potential effects of global warming on P. hirtus.
May 07, 2019
Exploring the temperature tolerance of a cave beetle
View comment
Hello there Tom, and many thanks for drawing the attention to Hadenoecus subterraneus (https://en.wikipedia.org/wiki/Hadenoecus), the cave beetle's food supplier. Indeed, I fully agree with that our data indeed imply that Hadenoecus subterraneus's well being would become the more immediately pressing issue when it comes to the potential effects of global warming on P. hirtus.
May 07, 2019
Exploring the temperature tolerance of a cave beetle
View comment
OK people. 8 votes in meaning 2 guesses away from disclosure. Come on, we can do this! Recovering from polar vortex time...
Jan 31, 2019
Exploring the temperature tolerance of a cave beetle
View comment
Jeff's excellent comment warrants some more information: In our experiment, short-term tolerance was defined as survival for 5 days. We started the experimental cultures at 11 degrees Celsius and increased the temperature by 2 degrees every 5 days. If anyone feels compelled to revise their initial guesstimate, please go ahead!
Jan 29, 2019
Exploring the temperature tolerance of a cave beetle
View comment
Wow. Halfway there in 24 hours. And a very interesting spread of temps... Glad I started this. 4 more guesstimates needed. Polls will be open until the weekend no matter what! Thanks for everyone's input so far.
Jan 29, 2019
Exploring the temperature tolerance of a cave beetle
View comment
Genes potentially showing degeneration in P. hirtus: For this, we would need the genome sequence... which we've asked to be funded quite a number of times in the past (Hello NSF!). And comparative transcriptomes from surface relatives. Based on the transcriptome data we published in 2011 (doi: 10.1242/jeb.060368), I would think the eye pigmentation genes we couldn't detect to be expressed represent candidates for genes in the process of degeneration.
Jan 18, 2019
Exploring the temperature tolerance of a cave beetle
View comment
Hi there Steve! Great point of course. The number of 5 million years as the age of P. hirtus age is indeed based on the simplifying assumption that there were no further, now extinct lineages that branched off the terminal branch to P. hirtus in our tree. A more careful statement would be that our tree times the origin of the last common ancestor that gave rise to modern P. hirtus plus possibly extinct relatives in relation to the other members of the hirtus-group. While the paleontological evidence is, to the best of my knowledge, too limited to explore this, we are hopeful to get further insights some day by timing the onset of gene degeneration related to cave colonization and adaptation, which be great to compare to the subterranean dytiscids and other subterranean clades.
Jan 14, 2019
Exploring the temperature tolerance of a cave beetle
View comment
Show more comments