Scavenging interactions between the arrow tooth eel Synaphobranchus kaupii and the Portuguese dogfish Centroscymnus coelolepis

Abstract

A scavenging interaction between the arrow tooth eel Synaphobranchus kaupii and the Portuguese dogfish Centroscymnus coelolepis, both ubiquitous components of fish assemblages at bathyal depths, was observed. Using a baited camera between 1297 and 2453 m in the eastern Atlantic Ocean continental slope, it was shown that despite consistently rapid arrival times of S. kaupii (<5 min), their feeding bouts (indicated by acute peak in numbers) did not take place until shortly after C. coelolepis arrived and removed the exterior surface of the bait (skipjack tuna Katsuwonus pelamis carcass). Change in the numbers of S. kaupii was hence dependent on the arrival of a more powerful scavenger throughout the study site, and at the deeper stations where the population of C. coelolepis declined, S. kaupii was observed to be present but waited for >2 h before feeding, thus contradicting conventional scavenging assumptions in the presence of a food fall.

Fish Food in the Deep Sea: Revisiting the Role of Large Food-Falls

“…Pachycara crassiceps , which have also been observed at baited camera traps in this area [49]. No active feeding on the carcass was observed, and most of the fish remained stationary on or near the carcass.…”

“…Of these, only Synaphobranchus and Pachycara were observed at the elasmobranch carcasses in this study. The reduced feeding of C. coelolepis at the carcasses (discussed above) would have also hindered the feeding of S. parasitica , which is reliant C. coelolepis to tear through the tough skin and expose soft flesh [49]. The total dominance of zoarcid fish at these carcasses, with occasional appearances of myxinids, macrourids and synaphobranchids is in keeping with scavenging community composition at experimental bait deployments in the Arabian Sea [51].…”

“…If this phenomenon extends to deep-sea scavenging elasmobranchs, it can be assumed that the Portugese dogfish, Centroscymnus coelolepis , would have been deterred from scavenging the elasmobranch carcasses. This will have severely hindered utilization of the carcasses by other species, since C. coelolepis is the dominant scavenger off the Angola margin [49].…”

“…An extensive baited camera study off Angola (13 sites between 1293 m and 2453 m) showed that five species dominated the local scavenging assemblage: the Portuguese dogfish Centroscymnus coelolepis , the snubnosed eel Simenchelys parasitica , the arrow tooth eel Synaphobranchus kaupii , the blue hake Antimora rostrata and Pachycara crassiceps [49]. Of these, only Synaphobranchus and Pachycara were observed at the elasmobranch carcasses in this study.…”

Investigating Trophic Interactions of Deep-sea Animals (Sharks, Teleosts, and Mobile scavengers) in the Gulf of Mexico Using Stable Isotope Analysis

“…They may also be reliant on other scavenger species with better dentition than themselves for access to large food items. Jamieson et al (2011) found that Centroscymnus coelolepis, the Portuguese Dogfish Shark, facilitated scavenging by S. kaupii by removing the exterior surface of larger food items, in this case, bait. In the absence of the sharks, the Cutthroat Eels often waited more than two hours before feeding.…”