Data and code from: Chemical cues facilitate foraging across the water-land interface in a resident predatory fish

Transitional ecosystems, such as the land-sea interface, propagate nutrient flow and species interactions. Organisms spanning these boundaries act as important models for understanding of the evolution of sensory modalities that promote movement between physically distinct media, and the ecological consequences of ecosystem connectivity. Behavior is fundamentally guided by sensory processing, yet how sensory information is transmitted and collected is heavily dependent on the physical environmental medium. The flow of stimuli across the land-sea interface and the behavioral responses to stimuli are understudied. Vertebrates that span the land-sea boundary offer the opportunity to document how stimuli can be used to complete complex behaviors across transitional ecosystems. We determined that California moray eels (Gymnothorax mordax) can use chemical stimuli (odor and taste) to locate prey across intertidal boundaries on Santa Catalina Island. We tested moray responses to chemical stimu..., Study location & sampling sites
University of Southern California’s Wrigley Marine Science Center in Big Fisherman Cove on Santa Catalina Island, California (33.4452, - 118.4847). 
Chemical stimuli
Prey Stimuli: kelp bass (Paralabrax clathratus), two-spot octopus (Octopus bimaculoides), anchovy (Engraulis sp.), and California market squid (Doryteuthis opalescens)
Control: 50 μm filtered seawater

Trial format & experimental apparatus
Our experimental apparatus was designed to administer controlled pulses of chemical stimuli into a target area within our sample site. The experimental apparatus was fixed with an underwater camera (GoPro Hero 8), recording the entire duration of the trial. Treatments were injected to the site via vinyl tubing (4 mm diameter) into a 30 cm long, 10 cm diameter white PVC tube. The PVC tube acted as a “foraging crevice” (mimicking rocky crevices in the habitat) and is henceforth referred to as the “target”. The target required morays to navi..., # **Title:** ***Chemical cues facilitate foraging across the water-land interface in a resident predatory fish***

# Authors:

**Maya M. McElfish** - University of California Santa Cruz \
Contact Information - [[e-mail]](mailto:[e-mail]) or [[e-mail]](mailto:[e-mail])

Nicholas A. Hess - Eckerd College\
Helena B. Lewis - Eckerd College\
Sacha E. O'Connor - University of California Santa Cruz\
Rita S. Mehta - University of California Santa Cruz

# Research Goals:

1. Document if *Gymnothorax mordax* can use chemical stimuli alone to detect prey and to navigate to a specific prey location
2. Assess if behavioral responses vary between chemical cues from different prey species
3. Test if these cues can be used in both fully submerged and partial exposed (intertidal) contexts.

# **General Experimental Details:**

We conducted two summers (2022, 2023) of field-based behavioral experiments in Big Fisherman Cove on Santa Catalina Island, Califor..., , **Changes after Dec 3, 2025:** \
Modified analysis code to replace absolute file paths with relative paths -- \
Data files are unchanged.

Line 81: MultiSummerData <- read.csv(\"../data/MultiSummer.csv\")