pith. sign in

arxiv: 2606.23245 · v1 · pith:3XTQH5B6new · submitted 2026-06-22 · 🧬 q-bio.QM

Predator-associated cues promote host riding, and coupling to mobile hosts improves survival in an epizoic limpet

Ryo Nakayama , Tomoyuki Nakano , Keita Harada , Katsushi Kagaya This is my paper

Pith reviewed 2026-06-26 06:04 UTC · model grok-4.3

classification 🧬 q-bio.QM
keywords epizoic limpetLottia tenuisculptahost ridingpredator cuesattachment behaviorsurvival assaymucus conditioning
0
0 comments X

The pith

Crab cues increase limpet attachment to hosts while riding mobile hosts raises survival rates.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper shows that cues from crabs raise the rate at which epizoic limpets attach to mobile gastropod hosts and that this attachment improves survival. In controlled chambers crab cues lifted attachment from 19 of 80 limpets to 42 of 76 and produced closer approach distances in the minutes before riding. Survival models fitted to separate trials found a hazard ratio of 2.111 favoring mobile over fixed hosts, with end-of-window survival at 0.437 versus 0.175. Host mucus alone also narrowed the paths taken by solitary limpets. A reader would care because the work ties a detectable predator signal to a specific behavioral sequence and a measurable survival payoff.

Core claim

In the host-riding assay crab-associated cues raised attachment counts and shallowed the high-frequency tail of the locomotor amplitude spectrum (posterior median slope from -0.353 to -0.287). Paired-trajectory analysis showed stronger distance closure under the same cues. The survival assay produced a posterior median hazard ratio of 2.111 for fixed versus mobile hosts and posterior median survival probabilities of 0.437 on mobile hosts versus 0.175 on fixed hosts. Mucus-conditioned surfaces reduced the final cumulative-distance range of single limpets relative to controls.

What carries the argument

Host-riding response to predator cues, quantified by attachment counts, spectral analysis of locomotion, visible paired-trajectory distance closure, and survival hazard models.

If this is right

  • Crab cues raise attachment rates inside the observation window.
  • Paired trajectories show a measurable pre-riding approach component that strengthens under cues.
  • Attachment to mobile hosts produces lower mortality than attachment to fixed hosts.
  • Host mucus alone can restrict the final distance range traveled by solitary limpets.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Limpets appear able to use chemical predator signals to decide when to initiate host-seeking movement.
  • The same cue-driven attachment logic could operate in other epizoic marine invertebrates facing mobile predators.
  • Direct field counts of attachment frequency across gradients of crab density would test whether the lab pattern scales to natural populations.

Load-bearing premise

The cue and host-mobility treatments isolate crab signals and mobility without unmeasured differences in water chemistry, host identity, or limpet condition altering attachment or survival.

What would settle it

Repeating the host-riding assay and finding no difference in attachment rates between cue-present and cue-absent chambers would falsify the claim that predator cues promote riding.

Figures

Figures reproduced from arXiv: 2606.23245 by Katsushi Kagaya, Keita Harada, Ryo Nakayama, Tomoyuki Nakano.

Figure 1
Figure 1. Figure 1: Experimental design and tracking setup. (A) Survival assay for Lottia tenuisculpta riding on the shell of Tegula nigerrima. The host snail was either fixed to the chamber floor or allowed to remain mobile, whereas the limpet was never restrained. The event was predation on the limpet. (B) Riding assay for the response of L. tenuisculpta to predator-associated waterborne cues. Each chamber contained one hos… view at source ↗
Figure 2
Figure 2. Figure 2: Crab-associated cues increased host riding and revealed a visible final approach component in paired [PITH_FULL_IMAGE:figures/full_fig_p013_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Host mobility increased limpet survival probability. [PITH_FULL_IMAGE:figures/full_fig_p014_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Mucus-conditioned surfaces changed cumulative-distance trajectories relative to same-individual [PITH_FULL_IMAGE:figures/full_fig_p015_4.png] view at source ↗
read the original abstract

Epizoic limpets may reduce predation risk by riding mobile gastropod hosts, but the behavioral steps leading to host attachment and the benefits of attachment remain poorly understood. We examined these issues in the epizoic limpet $\textit{Lottia tenuisculpta}$ using a host-riding assay, paired-trajectory analyses of pre-riding movement, a survival assay, and mucus-conditioning assays. In the host-riding experiment, involving 156 limpets in 39 chambers, crab-associated cues increased attachment within the observation window from 19 of 80 individuals in the cue-absent treatment to 42 of 76 individuals in the cue-present treatment. In the same assay, the high-frequency tail of the locomotor amplitude spectrum became shallower under cue-present conditions, with the posterior median slope shifting from -0.353 to -0.287. Direct analysis of visible paired host-limpet trajectories further showed stronger distance closure under crab-associated cues. Distance closure was quantified over the final visible five minutes before riding or before the final visible paired frame. In the survival assay, based on 31 valid trials, the fitted model indicated lower survival after attachment on fixed hosts than on mobile hosts: the posterior median hazard ratio for fixed versus mobile hosts was 2.111, and posterior median survival at the end of the observation window was 0.437 on mobile hosts but 0.175 on fixed hosts. In a separate single-limpet locomotion assay, gastropod mucus-conditioned surfaces yielded narrower final cumulative-distance ranges than the no-mucus control. Together, these results indicate that predator-associated cues promote host riding, visible paired trajectories reveal a pre-riding approach component, coupling to mobile hosts improves survival, and host-associated surface cues may narrow solitary-limpet movement.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 2 minor

Summary. The paper examines behavioral and survival benefits of host riding in the epizoic limpet Lottia tenuisculpta. Using a host-riding assay with 156 limpets, it reports that crab-associated cues raise attachment from 19/80 to 42/76 individuals and shallow the high-frequency tail of the locomotor amplitude spectrum (posterior median slope from -0.353 to -0.287). Paired-trajectory analysis shows stronger distance closure under cues. A survival assay with 31 valid trials yields a posterior median hazard ratio of 2.111 for fixed vs mobile hosts, with survival probabilities 0.437 (mobile) vs 0.175 (fixed). Mucus-conditioning assays indicate narrower cumulative-distance ranges on conditioned surfaces.

Significance. If the central results hold, the work supplies direct experimental counts and posterior estimates linking predator cues to increased host attachment, pre-riding approach behavior, and a survival advantage for mobile-host coupling in an epizoic system. The multi-assay design and concrete sample sizes (156 limpets, 31 trials) are strengths that allow falsifiable claims about behavioral ecology. The survival finding, however, rests on a small sample whose robustness is not fully documented in the provided text.

major comments (1)
  1. [Abstract, survival assay description] Abstract, survival assay paragraph: the claim that coupling to mobile hosts improves survival rests on a model fitted to only 31 valid trials that produces a posterior median hazard ratio of 2.111 and survival probabilities 0.437 vs 0.175. No event counts, credible intervals, censoring details, or sensitivity checks to baseline hazard or priors are supplied; in survival analysis this sample size is small enough that a few influential observations or model choices could alter the result, making the estimate load-bearing for the survival-benefit conclusion.
minor comments (2)
  1. [Abstract] Abstract: the phrasing 'the high-frequency tail of the locomotor amplitude spectrum became shallower' and the slope values (-0.353 to -0.287) would benefit from a brief definition of the amplitude spectrum or a reference to the methods section where it is defined.
  2. [Abstract] Abstract: the mucus-conditioning result is stated only qualitatively ('narrower final cumulative-distance ranges'); adding the actual ranges or a statistical summary would improve clarity.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their thoughtful review and for highlighting the need for greater transparency in the survival assay. We address the single major comment below and will incorporate additional details and checks in a revised manuscript.

read point-by-point responses

  1. Referee: [Abstract, survival assay description] Abstract, survival assay paragraph: the claim that coupling to mobile hosts improves survival rests on a model fitted to only 31 valid trials that produces a posterior median hazard ratio of 2.111 and survival probabilities 0.437 vs 0.175. No event counts, credible intervals, censoring details, or sensitivity checks to baseline hazard or priors are supplied; in survival analysis this sample size is small enough that a few influential observations or model choices could alter the result, making the estimate load-bearing for the survival-benefit conclusion.

    Authors: We agree that the survival assay relies on a modest number of valid trials (31) and that the submitted manuscript does not report event counts, credible intervals, censoring information, or sensitivity analyses. These omissions make it difficult for readers to evaluate robustness. In the revision we will add: (i) the observed number of events (deaths) in the fixed-host and mobile-host groups, (ii) 95% credible intervals for the hazard ratio and for the reported survival probabilities, (iii) explicit description of any right-censoring that occurred, and (iv) results of sensitivity checks that vary the baseline hazard specification and the prior distributions. These additions will be placed in both the Methods and Results sections so that the survival-benefit claim can be assessed more fully while preserving the original experimental design and sample size. revision: yes

Circularity Check

0 steps flagged

No circularity: results from direct experiments and standard statistical analysis of new data

full rationale

The paper presents empirical findings from new assays (host-riding with 156 limpets, survival with 31 trials, mucus-conditioning, paired trajectories). Attachment rates, spectral slopes, distance closure, and hazard ratios are measured or fitted directly to the collected data. No equations, self-citations, or prior parameters are invoked such that any reported outcome reduces to a quantity defined by construction from the inputs. The derivation chain is self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 0 invented entities

This is an experimental study; the central claims rest on the validity of the behavioral and survival assays plus standard Bayesian statistical assumptions rather than on new mathematical derivations or postulated entities.

free parameters (1)
  • posterior median hazard ratio
    Fitted value (2.111) obtained from survival model applied to the 31-trial dataset.
axioms (1)
  • standard math Bayesian survival model assumptions hold for the hazard-ratio estimation
    Invoked to obtain posterior medians for hazard ratio and endpoint survival probabilities.

pith-pipeline@v0.9.1-grok · 5876 in / 1199 out tokens · 35559 ms · 2026-06-26T06:04:58.878040+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

26 extracted references · 23 canonical work pages

  1. [1]

    Hoffman, Daniel Lee, Ben Goodrich, Michael Betancourt, Marcus Brubaker, Jiqiang Guo, Peter Li, and Allen Riddell

    Stan: A probabilistic programming language.Journal of Statistical Software76:1–32. URL: https: //doi.org/10.18637/jss.v076.i01 Chialvo DR

    work page doi:10.18637/jss.v076.i01

  2. [2]

    URL:https://doi.org/10

    Emergent complex neural dynamics.Nature Physics6:744–750. URL:https://doi.org/10. 1038/nphys1803 ClinchyM,SheriffMJ,ZanetteLY.2013. Predator-inducedstressandtheecologyoffear.FunctionalEcology27:56–65. URL:https://doi.org/10.1111/1365-2435.12007 Codling EA, Plank MJ, Benhamou S

    work page doi:10.1111/1365-2435.12007 2013

  3. [3]

    URL:https://doi.org/10.1098/rsif.2008.0014 Dalesman S, Rundle SD, Coleman RA, Cotton PA

    Random walk models in biology.Journal of the Royal Society Interface 5:813–834. URL:https://doi.org/10.1098/rsif.2008.0014 Dalesman S, Rundle SD, Coleman RA, Cotton PA

    work page doi:10.1098/rsif.2008.0014 2008

  4. [4]

    URL: https://doi.org/10.1016/j.anbehav.2005

    Cue association and antipredator behaviour in a pulmonate snail,Lymnaeastagnalis.AnimalBehaviour71:789–797. URL: https://doi.org/10.1016/j.anbehav.2005. 05.028 Dalesman S, Rundle SD, Cotton PA

    work page doi:10.1016/j.anbehav.2005 2005

  5. [5]

    URL:https://doi.org/10.1111/ j.1365-2427.2007.01843.x Gelman A, Hill J

    Predator regime influences innate anti-predator behaviour in the freshwater gastropodLymnaea stagnalis.Freshwater Biology52:2134–2140. URL:https://doi.org/10.1111/ j.1365-2427.2007.01843.x Gelman A, Hill J. 2007.Data Analysis Using Regression and Multilevel/Hierarchical Models. Cambridge University Press. URL:https://doi.org/10.1017/CBO9780511790942 Houck...

    work page doi:10.1017/cbo9780511790942 2007

  6. [6]

    URL: https://doi.org/10.1111/j.0030-1299.2004.12369.x Kagaya K, Nakano T, Nakayama R

    Antipredator behaviour mediated by chemical cues: the role of conspecific alarm signalling and predator labelling in the avoidance response of a marine gastropod.Oikos104:43–50. URL: https://doi.org/10.1111/j.0030-1299.2004.12369.x Kagaya K, Nakano T, Nakayama R

    work page doi:10.1111/j.0030-1299.2004.12369.x 2004

  7. [7]

    URL:https://doi.org/10.20965/ jrm.2025.p0099 Kano Y

    Multiple power laws and scaling relation in exploratory locomotion of the snailTegula nigerrima.Journal of Robotics and Mechatronics37:99–104. URL:https://doi.org/10.20965/ jrm.2025.p0099 Kano Y

    2025

  8. [8]

    URL:https://doi.org/10.1098/rsbl.2009.0191 Kats LB, Dill LM

    Hitchhiking behaviour in the obligatory upstream migration of amphidromous snails.Biology Letters 5:465–468. URL:https://doi.org/10.1098/rsbl.2009.0191 Kats LB, Dill LM

    work page doi:10.1098/rsbl.2009.0191 2009

  9. [9]

    URL: https://doi.org/10.1080/11956860.1998.11682468 Lima SL

    Chemosensory assessment of predation risk by prey animals.Écoscience5:361–394. URL: https://doi.org/10.1080/11956860.1998.11682468 Lima SL

    work page doi:10.1080/11956860.1998.11682468 1998

  10. [10]

    URL: https://doi.org/10.2307/1313225 Lima SL, Dill LM

    Nonlethal effects in the ecology of predator-prey interactions.BioScience48:25–34. URL: https://doi.org/10.2307/1313225 Lima SL, Dill LM

    work page doi:10.2307/1313225

  11. [11]

    URL:https://doi.org/10.1139/z90-092 Mapstone BD, Underwood AJ, Creese RG

    Behavioral decisions made under the risk of predation: a review and prospectus.Canadian Journal of Zoology68:619–640. URL:https://doi.org/10.1139/z90-092 Mapstone BD, Underwood AJ, Creese RG

    work page doi:10.1139/z90-092

  12. [12]

    URL:https://doi.org/10.3354/meps017085 Mathis A, Mamidanna P, Cury KM, Abe T, Murthy VN, Mathis MW, Bethge M

    Experimental analyses of the commensal relation between intertidal gastropodsPatelloida mufriaand the trochidAustrocochlea constricta.Marine Ecology Progress Series17:85–100. URL:https://doi.org/10.3354/meps017085 Mathis A, Mamidanna P, Cury KM, Abe T, Murthy VN, Mathis MW, Bethge M

    work page doi:10.3354/meps017085

  13. [13]

    Cury, Taiga Abe, Venkatesh N

    DeepLabCut: markerless pose estimation of user-defined body parts with deep learning.Nature Neuroscience21:1281–1289. URL: https://doi.org/10.1038/s41593-018-0209-y Morales JM, Haydon DT, Frair J, Holsinger KE, Fryxell JM

    work page doi:10.1038/s41593-018-0209-y

  14. [14]

    URL:https://doi.org/10.1890/ 03-0269 NakayamaR,NakanoT,AsakuraA.2022

    Extracting more out of relocation data: building movement models as mixtures of random walks.Ecology85:2436–2445. URL:https://doi.org/10.1890/ 03-0269 NakayamaR,NakanoT,AsakuraA.2022. SubstratevarietyandhostpreferenceoftheepizoiclimpetLottiatenuisculpta (Patellogastropoda: Lottiidae).Molluscan Research42:31–40. URL:https://doi.org/10.1080/13235818. 2022.2...

    work page doi:10.1080/13235818 2022

  15. [15]

    URL:https://doi.org/10.18941/venus.83.1-4_111 10 Nakayama R, Nakano T, Yusa Y

    Selective settlement of the planktonic larvae of the epizoic limpetLottia tenuisculpta (Patellogastropoda: Lottiidae).Venus83:111–120. URL:https://doi.org/10.18941/venus.83.1-4_111 10 Nakayama R, Nakano T, Yusa Y

    work page doi:10.18941/venus.83.1-4_111

  16. [16]

    URL:https://doi.org/10.1016/j.jembe.2020.151402 Nathan R, Getz WM, Revilla E, Holyoak M, Kadmon R, Saltz D, Smouse PE

    Seasonal utilization patterns of two snail hosts by the epizoic limpet Lottia tenuisculpta(Gastropoda: Patellogastropoda).Journal of Experimental Marine Biology and Ecology 530–531:151402. URL:https://doi.org/10.1016/j.jembe.2020.151402 Nathan R, Getz WM, Revilla E, Holyoak M, Kadmon R, Saltz D, Smouse PE

    work page doi:10.1016/j.jembe.2020.151402 2020

  17. [17]

    URL:https://doi.org/10.1073/pnas.0800375105 Nicholson-JackAE,HarrisJL,BallardK,TurnerKME,StevensGMW.2021

    A movement ecology paradigm for unifying organismal movement research.Proceedings of the National Academy of Sciences of the United States of America105:19052–19059. URL:https://doi.org/10.1073/pnas.0800375105 Nicholson-JackAE,HarrisJL,BallardK,TurnerKME,StevensGMW.2021. Ahitchhikerguidetomantarays: patterns of association betweenMobula alfredi,M. birostr...

    work page doi:10.1073/pnas.0800375105 2021

  18. [18]

    URL: https://doi.org/10.1016/j.tree.2007.10.009 Preisser EL, Bolnick DI, Benard MF

    State-space models of individual animal movement.TrendsinEcology&Evolution23:87–94. URL: https://doi.org/10.1016/j.tree.2007.10.009 Preisser EL, Bolnick DI, Benard MF

    work page doi:10.1016/j.tree.2007.10.009 2007

  19. [19]

    URL:https://doi.org/10.1890/04-0719 Singer JD, Willett JB

    Scared to death? The effects of intimidation and consumption in predator-prey interactions.Ecology86:501–509. URL:https://doi.org/10.1890/04-0719 Singer JD, Willett JB

    work page doi:10.1890/04-0719

  20. [20]

    URL: https://doi.org/10.1111/j.1461-0248.2004.00719.x Stan Development Team

    Local adaptation in host use among marine invertebrates.Ecology Letters8:448–459. URL: https://doi.org/10.1111/j.1461-0248.2004.00719.x Stan Development Team. 2026.Stan Reference Manual, Version 2.38. URL: https://mc-stan.org/docs/ reference-manual/ Turner AM, Bernot RJ, Boes CM

    work page doi:10.1111/j.1461-0248.2004.00719.x 2004

  21. [21]

    URL:https://doi.org/10.1034/j.1600-0706

    Chemical cues modify species interactions: the ecological consequences of predator avoidance by freshwater snails.Oikos88:148–158. URL:https://doi.org/10.1034/j.1600-0706. 2000.880117.x Turner AM, Fetterolf SA, Bernot RJ

    work page doi:10.1034/j.1600-0706 2000

  22. [22]

    URL:https://www.biodiversitylibrary

    Good hosts and their guests: relations between trochid gastropods and the epizoic limpetCrepidula adunca.The Nautilus101:69–74. URL:https://www.biodiversitylibrary. org/page/8097562 Wada Y, Noda T, Ida TY, Iwatani Y, Sato T

    arXiv

  23. [23]

    URL:https://doi.org/10

    Tracing the battle: role of mucus trails in information warfare between predator snail and prey limpet.Journal of Animal Ecology95:851–864. URL:https://doi.org/10. 1111/1365-2656.70235 Wahl M

    arXiv

  24. [24]

    Marine epibiosis. I. Fouling and antifouling: some basic aspects.Marine Ecology Progress Series 58:175–189. URL:https://doi.org/10.3354/meps058175 Wahl M

    work page doi:10.3354/meps058175

  25. [25]

    URL:https://doi.org/10.1080/08927010802339772 Werner EE, Peacor SD

    Ecological lever and interface ecology: epibiosis modulates the interactions between host and environment.Biofouling24:427–438. URL:https://doi.org/10.1080/08927010802339772 Werner EE, Peacor SD

    work page doi:10.1080/08927010802339772

  26. [26]

    URL:https://doi.org/10.1890/0012-9658(2003)084%5B1083:AROTII%5D2.0.CO;2 Yarnall JL

    A review of trait-mediated indirect interactions in ecological communities.Ecology 84:1083–1100. URL:https://doi.org/10.1890/0012-9658(2003)084%5B1083:AROTII%5D2.0.CO;2 Yarnall JL

    work page doi:10.1890/0012-9658(2003)084 2003