1. #Tuna have well-developed bilateral keels extending to the right and left sides at the caudal peduncle area just in front of the tail. This movie shows the keel area during locomotion in yellowfin tuna. What is the function of keels in #tuna? A🧵 and new hypothesis.

Our new paper is out as OA! shorturl.at/BueUy Tuna keels aren't just for hydrodynamics—they're mechanosensory! 🐟 They contain a modified lateral line, possibly adapted to detect stimuli in high-noise environments @georgelauder.bsky.social @jackiew8.bsky.social + Dylan Wainwright + Connor White

What is the function of the elongate tail in elasmobranch #rays? A 🧵 and a new hypothesis. A paper with @juliachaumel.bsky.social in @royalsociety.org Proceedings B (shorturl.at/PmfYD) shows that the tail of cownose rays (and a few other species studied so far) has an elaborate lateral line.

What is the significance of the tremendous diversity of #shark skin #denticles? Presenting our experimental approach to understanding this at the Atlanta #SICB2025 meetings. Come to the session for all things shark skin!

Why do #fish swim in #schools? A🧵and new hypothesis. Schooling could help fish avoid predators, navigate, communicate, find mates and food, and save energy. Here we propose and test a new hypothesis: https://tinyurl.com/yc764d74

Do #fish swimming in a #school actually save energy? A🧵on this as our paper in @eLife https://elifesciences.org/articles/90352#fish#schooly @TheYangfanZHANG addresses this question. This is a challenging issue to study: energy use by a school should be compared to solitary locomotion

Do #fish swimming in a #school actually save energy? Our paper on this in eLife elifesciences.org/articles/90352 addresses this question. This is a challenging issue: energy use by a school needs to be compared to solitary locomotion on a per gram basis under the same swimming conditions.

The shark #denticle #multiverse will be on display at #sicb2024 this week. See talks in the @SICB_DCB_DVM sessions. So much diversity, so little time ... below the #ontogeny of sleeper shark denticles from Vaz et al. 2023: mdpi.com/1424-2818/15...

The shark #denticle #multiverse will be on display at #sicb2024 this week. See talks in the @SICB_DCB_DVM sessions. So much diversity, so little time ... below the #ontogeny of sleeper shark denticles from Vaz et al. 2023: https://www.mdpi.com/1424-2818/15/11/1105

Getting ready for #SICB2024, and all things #shark skin! Testing patches of skin to measure the shear stress (friction) of water moving over the skin, and how #denticle orientation alters flow patterns.

Getting ready for #SICB2024, and all things #shark skin! Testing patches of skin to measure the shear stress (friction) of water moving over the skin, and how #denticle orientation alters flow patterns.

Our accessible Sharks Summer REU is running in 2024. Unique opportunity for disabled undergraduates interested in sharks, paleobiology, developmental biology, and bio-inspired design. Apps due Jan 19. #NSFFunded #DisabledInSTEM. Please repost and spread the word! accessiblesharks.wordpress.com

This past summer Elizabeth Sibert, Gareth Fraser, and I ran an "Accessible Sharks" REU program as part of our NSF grant. Story here ... and we're running it next summer too! https://news.harvard.edu/gazette/story/2023/08/accessible-science-students-disabilitiesnts-sharks-denticles-hydrodynamics/

Why might #fish in a #school swim behind one another? A🧵.This question arises because being behind another fish involves #swimming in faster flow. A cyclist can draft because oncoming velocity is reduced. A thrust wake is like a cyclist facing a leader with a large fan.

The #shark #denticle #multiverse is vast, and @MarBioMoll will present at #SICB2023 on ontogenetic changes in skin denticles in leopard sharks. So much variation and so few previous studies of denticle ontogeny @SICB_ @SICB_DCB_DVM

Gearing up for the #SICB2023 meetings … first up is the #shark #denticle #multiverse! Talks by @dfbvaz and Tess Avery will describe remarkable changes in denticles during ontogeny in the Portuguese dogfish, accompanied by lots of variation around the body @SICB_ @SICB_DCB_DVM

The fields of #robotics and #ecology and #evolution would not seem to have that much in common. A thread on why robotic mechanisms are so useful and constitute another “comparative method” in the toolbox of organismal biologists, discussed here: https://bit.ly/3Hv85Hr

Very excited to have been a small “fishy” part of the next @DeepLabCut with @valdisanto out now in @naturemethods (https://go.nature.com/3Jzo72d). Multi-animal pose estimation and tracking led by Mackenzie W. Mathis @TrackingActions and Alexander Mathis @TrackingPlumes

A small robotic fish powered by human heart cells??!! A thread on biohybrid robots to celebrate the large collaborative effort just out in Science (https://bit.ly/3Jj13VS)

Most fish have very flexible bodies as seen here in an anesthetized trout. But how stiff should fish be to swim effectively, and how can fish (and robots) modulate their body stiffness to improve swimming performance? – a thread.

What role can #robotics play in #ecology and evolutionary biology? – a thread. My talk at #SICB2022 has the goal of discussing why and how I think that robotics should be thought of as a “comparative method” @SICB_DCB_DVM.

The amazing skin of sharks: a (longish) thread! For some time we’ve been studying the structure and function of #shark #skin and #biomimetic models of shark surfaces. Covered with amazing dermal #denticles (#scales) sharks have skin with a rough texture composed of tiny teeth.

How do #fish swim? A thread! Since the 1990s I’ve been wondering if the canonical categories used to describe fish #locomotion are valid. This classic diagram from Lindsey (1978) has been published in almost every fish biology text book and review article on aquatic propulsion.

Many thanks to @MariaKaimaki for her very nice report on our paper published in @BioinspBiomim on #robotic models of #fish #fin function during swimming led by @Orang_Hutan_ #robots #locomotion http://shorturl.at/rQT13

A bit more on #fish #fins in series! Using a simple #robotic model our paper (https://bit.ly/2WYMNzd#fish#fins#roboticed by grad student Dave Matthews @Orang_Hutan_ shows experimentally how flow from one fin affects the fin behind. Visualization of flow interactions using #PIV is mesmerizing!

Fish often have multiple #fins in series … how does this influence #swimming force generation and efficiency? Our new paper (https://bit.ly/2WYMNzd#fins#swimmingled by grad student Dave Matthews @Orang_Hutan_ uses simple robotic flapping foil models to measure this! #fish #robotics

Shark skin from Genotype to Phenotype to Prototype! That’s our new collaborative @NSF grant slogan with the IntBIO program. Super excited to work with @garethjfraser and @elizabethsibert to understand shark denticle evolution, development, design, and function!

Many congratulations to @elizabethsibert and @SoundsFishyLeah for the publication of their outstanding paper in @ScienceMagazine on #shark diversity through time using #denticles in deep-sea sediments (https://bit.ly/2TKROtf#shark#denticles Such weird denticles in extinct species!

We demonstrated the principles of in-line energy savings during #fish #schooling both with computations and a fish robotic model: the #robot has a rigid static foil held in the immediate tail wake. Energy cost of #swimming is reduced with the foil present … movie in next tweet!

Weihs (1973:p290) suggested that #fish #schools should arrange in a “diamond pattern” to prefer positions inbetween leading fish due to reduced velocity, and that “A fish situated directly behind A would experience a higher relative velocity and would have to exert extra energy”

We’re working away in the lab on #fish #schooling from a variety of perspectives, so here’s a new thread to celebrate publication of “Hydrodynamic advantages of in-line schooling” in @BioinspBiomim https://bit.ly/3eBM7FS#fish#schooling First, recall the classic Weihs 1973 paper and figure:

Fish and #robots … what could be better!? Recent paper (https://bit.ly/3bD6kth#robots by Carl White @BIERLABS1 has two very useful tables summarizing #swimming robots and their speed, tail beat frequency, and power used to swim. Here the TunabotFlex demonstrates low cost swimming.

New paper on #tuna robotics is out! The TunabotFlex system developed by Carl White in @BIERLABS1 @UVA (paper at https://bit.ly/3bD6kth#tuna shows high-performance, self-propelled, low cost #swimming with body flexibility and tuna-like kinematics. #locomotion #robot #fish

A robotic #tuna accelerates from rest! New paper (https://bit.ly/3u9qiDp#tuna in @royalsociety B led by @rthandiackal uses a robotic tuna developed by Carl White @BIERLABS1 @UVA to show how body surface pressures and forces develop as propulsion begins. #locomotion #robot #fish

Very proud of all co-authors on the work to develop the first multi-fin, closed-loop, autonomous, small fish-like #robot. Very useful for testing hypotheses about fish swimming and schooling behavior … more to come! Paper at https://bit.ly/3qpIeaF#robot #swimming #fishsci

Polypterus: so many #finlets … so little known about their locomotor function. And auto-tracking multiple finlets during a variety of locomotor behaviors is not easy! Talk by Zane Wolf (@inzaneresearch) at #SICB2021 here: https://bit.ly/3iZMCdg#finlets#SICB2021 #fishsci @SICB_DCB_DVM

Batrachoidiform #fish reproduce in the rocky intertidal and have large benthic eggs. How does this alter skeletal development in the head? Talk by Diego Vaz (@dfbvaz) EO Wilson Postdoc @Harvard at the #SICB2021 meeting here: https://bit.ly/2MhTOpk#fish#SICB2021 #fishsci @SICB_DCB_DVM

So great to welcome Dr. Whitney Preisser (@WCPreisser) to @MCZHarvard this fall to join Diego Vaz (@dfbvaz) as an Edward O. Wilson Biodiversity Postdoc Fellow working in the Fish Dept. and with @ggiribet. We're all looking forward to learning more about #fish #parasites from her!

How does the fibrosis response to parasites affect the escape response in #stickleback fishes? @Orang_Hutan_ with @DanielBolnick lab has shown the effects of fibrosis on body stiffness. Our talk at #SICB2021 here: https://bit.ly/3qtVsCG#stickleback#SICB2021#fishsci #locomotion @SICB_DCB_DVM

Can fish save energy when #swimming in oscillatory flows with increased velocity? Experiments using our robotic flapper by @rthandiackal show that even in a thrust wake trout alter body kinematics to reduce cost. Talk at #SICB2021… more to come! @SICB_DCB_DVM #fishsci

#Shark skin #denticles are remarkably diverse, but the external skin between gill slits shows a new pattern. @molly_gabler shows a dramatic transition in denticle shape within a few mm in her #SICB2021 talk. #fishsci #sharks #SharkScience @SICB_DCB_DVM

I'm very excited to say that today my awesome collaborators and I were awarded U.S. Patent No. 10,882,606 for shark skin-inspired devices that improve hydrodynamics. Paper with all authors at https://bit.ly/2Xfn8yw. #fishsci #sharks #SharkScience

Studying acceleration from rest in live fishes is hard! @rthandiackal, Carl White in @BIERLABS1 at UVA, and I used a fish robot to generate accelerations and quantify power used and water flow dynamics. Talk @SICB2021. #fishsci #locomotion #hydrodynamics #SICB2021 @SICB_DCB_DVM

If you are interested in shark skin, fish robotics (3 talks), fish schooling (3 talks), fish finlets, and even stickleback parasites, check out the talks upcoming at the virtual #SICB2021 meetings from the @georgelauder lab and collaborators. #fishsci #sharkskin @SICB_DCB_DVM

Following up yesterday’s tweet from @rthandiackal on our #zebrafish locomotion work, it’s hard to overemphasize how detailed the velocity vector fields are using IR light and small algae as tracer particles. Paper in @J_Exp_Biol (https://bit.ly/3gwRrI5#zebrafish #swimming #fishsci

Studying #zebrafish turning maneuvers with @rthandiackal ... it’s critical to have multiple views to know where the fish is located in 3D, and great to use IR lights to enhance automated masking of the body. Paper in @J_Exp_Biol (https://bit.ly/3gwRrI5#zebrafish #swimming #fishsci

Some virtual #SharkScience featuring @molly_gabler and yours truly from @HarvardMuseum and @MCZHarvard, talking about shark anatomy and skin denticles. https://hmsc.harvard.edu/sharks#SharkScience#swimming #fishsci

Sharks are amazing! Great article by JoAnna Klein @nonojojo for @NatGeo describing fascinating new discoveries on shark biology over the past 10 years. Happy to be a part of this with @FABBLab @ProfSharkBrain @SeaScienceSam and others! https://on.natgeo.com/2BEuLY7 #SharkScience

It’s time for #SharkScaleSaturday again! Continuing with the theme of missing denticles, this tail surface of a leopard #shark is missing several. Missing #denticles occur all around the body of all species we’ve looked at so far. #swimming #fishsci #SharkScience

If you see a gap in denticles patterning the skin of #sharks, look inside! Images are SEMs of the exact same location taken with different electron beam angles to reveal the subsurface denticle emerging into the gap (https://bit.ly/2VFtlmY#sharks. #swimming #fishsci #SharkScience