Anglerfish Bacterial Symbionts and Seawater from the Northern Gulf of Mexico
Gulf of Mexico Oil Spill & Ecosystem Science Conference, New Orleans, LA, February 6-9, 2017
Female anglerfishes belonging to 9 out of 11 families (suborder Ceratioidei) develop a lure ("esca") containing bioluminescent bacterial symbionts. However, the source of symbionts remains unclear as previous work indicates the larval fish do not possess these bacterial symbionts in the immature escal organ, suggesting no vertical transmission. As part of the DEEPEND project (www.Deependconsortium.org), the objective of this study is to characterize the escal microbiomes of several deep-sea anglerfish species and to determine whether symbionts may be acquired horizontally from the water column. Because no active large oil spill existed during DEEPEND collections, these results reflect a GOM baseline of symbiont presence in the water and possible horizontal uptake to hosts after concomitant profiling of the pelagic habitat. Anglerfish were collected on four biannual cruises (DP01-DP04) in May and August of 2015 and 2016. Seawater samples were simultaneously collected via CTD-mounted Niskin bottles from a total of 38 sites. Escal specimens represented 24 mature individuals comprising a total of 6 anglerfish species: Cryptopsaras couesii, Melanocetus johnsonii, Dolopichthys sp., Ceratias uranoscopus, Melanocetus murrayi, and Centrophryne spinulosa. Larval anglerfish from the Oneirodidae, Linophrynidae, and Gigantactinidae families were also collected. High throughput 16S rRNA V4 sequencing revealed Vibrionaceae-like OTUs dominating the escal microbial community (up to 95.1% of relative abundance). Preliminary analyses from 2015 DP01 and DP02 cruises indicate lesser abundances of the Vibrionaceae symbiont on fish exteriors (skin, gills). A different symbiont was identified in both the M. johnsonii and Dolopichthys sp. escal specimens. Both symbiont types were identified within the seawater from nine DP02 sampling sites (C. couesii symbiont being most abundant), while neither was detected in cruise DP01. Ongoing analysis focuses on incorporating more specimens collected in 2016 as well confirming the seawater findings.
Freed, L.; Fenolio, D.; Easson, Cole; Hendry, T.; Sutton, Tracey; and Lopez, Jose V., "Anglerfish Bacterial Symbionts and Seawater from the Northern Gulf of Mexico" (2017). Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures. 449.