Dear colleagues,
Please find our new publication entitled: A common bottlenose dolphin (Tursiops truncatus)
prey handling technique for marine catfish (Ariidae) in the northern
Gulf of Mexico. Ronje EI, Barry KP, Sinclair C, Grace MA, Barros N,
Allen J, Balmer B, Panike A, Toms C, Mullin KD, Wells RS (2017) PLoS ONE 12(7): e0181179.
Abstract: Few accounts describe predator-prey interactions between common bottlenose dolphins (Tursiops truncatus Montagu 1821) and marine catfish (Ariopsis felis Linnaeus 1766, Bagre marinus Mitchill
1815). Over the course of 50,167 sightings of bottlenose dolphin groups
in Mississippi Sound and along the Florida coast of the Gulf of Mexico,
severed catfish heads were found floating and exhibiting movements at
the surface in close proximity to 13 dolphin groups that demonstrated
feeding behavior. These observations prompted a multi-disciplinary
approach to study the predator-prey relationship between bottlenose
dolphins and marine catfish. A review was conducted of bottlenose
dolphin visual survey data and dorsal fin photographs from sightings
where severed catfish heads were observed. Recovered severed catfish
heads were preserved and studied, whole marine catfish were collected
and examined, and stranding network pathology reports were reviewed for
references to injuries related to fish spines. Photographic
identification analysis confirms eight dolphins associated with severed
catfish heads were present in three such sightings across an
approximately 350 km expanse of coast between the Mississippi Sound and
Saint Joseph Bay, FL. An examination of the severed catfish heads
indicated interaction with dolphins, and fresh-caught whole hardhead
catfish (A. felis) were examined to estimate the presumed
total length of the catfish before decapitation. Thirty-eight instances
of significant trauma or death in dolphins attributed to ingesting whole
marine catfish were documented in stranding records collected from the
southeastern United States of America. Bottlenose dolphins typically
adhere to a ram-feeding strategy for prey capture followed by whole prey
ingestion; however, marine catfish skull morphology may pose a
consumption hazard due to rigid spines that can puncture and migrate
through soft tissue, prompting a prey handling technique for certain
dolphins, facilitating consumption of the posterior portion of the fish
without the head.
Regards,
Errol Ronje
Fisheries Biologist
IAP World Services Contractor
NOAA/NMFS/SEFSC - Mississippi Labs