Author: Christian K Fender,  PhD Candidate (Florida State University)

Designation: 

Description:
While the importance of salp grazing has become increasingly apparent in shaping their local ecosystems, recent work has called into question whether salp prey communities may vary between species, sizes, or life stages. This study investigated the feeding habits of 7 different species of salp of both solitary and aggregate life stages representing a variety of sizes across subtropical and subantarctic waters east of New Zealand.  Scanning electron microscopy was used to examine the gut contents for 59 salps. While most of the gut size spectra and taxonomy resembled ambient waters, substantial differences were found amongst some co-occuring species, such as an increased proportion of submicron bacteria in Thalia democratica compared to Ihlea maghalanica or the higher proportion of diatoms in Salpa thompsoni. This may suggest that salps exhibit niche partitioning, with certain co-occuring species occupying different trophic levels and ecological roles within the same water mass. Salp predator to prey size ratios were also significantly lower than generally reported with the majority at around 1000:1. Ongoing work will compare depth-resolved phytoplankton composition of ambient waters using HPLC, epifluorescence microscopy, and genetics to investigate the cause of these variations.

Category: Scientific Program Abstract > Special Sessions > SS67 The Fragile Food Web: Dynamics and impacts of gelatinous zooplankton and other understudied organisms