Sequencing annelid mitochondrial genes
Under a collaborative NSF-AToL Grant “WormNet II: Assembling the Annelid Tree of Life”, our lab will be sequencing up to 3000 annelid taxa for two mitochondrial markers. The data will help us resolve relationships among closely related species, address questions of cryptic diversity and study phylogeographic patterns in annelids.
Phylogeography of fireworms
Hermodice carunculata is a polychaete with a wide geographic distribution throughout the Caribbean, Gulf of Mexico, western and eastern Atlantic and the Mediterranean Sea. It is also known as the bearded fireworm, due to the fact that its chaetae break off at the smallest disturbance and can produce severe skin reactions. We are studying the genetic connectivity of populations throughout the species’ distribution range.
DNA based methods to detect non-indigenous species in Galveston Bay
We are using a DNA barcoding approach to genetically screen zooplankton for potentially invasive species. Plankton samples are taken from the shore and from six stations in various salinities and distances from the Houston Ship Channel. We photographically document the morphotypes of planktonic larvae and adults and sequence them for the mitochondrial COI gene, the most commonly used marker for DNA barcoding. This dataset will give us baseline data for future studies in dispersal and population structure of local and invasive species.
Zoëa larva of a crab
Macrofaunal diversity in the Sigsbee Abyssal Plain
The Sigsbee Abyssal Plain comprises a huge area of seafloor in the Southwestern Gulf of Mexico. While the sedimented bottom appears to be uniform, it probably shows variability at the scale of the organisms that inhabit it. We have collected macrofaunal samples from seven stations and have sorted and identified the organisms. We are currently working on their genetic diversity. This project is conducted in collaboration with Mexican researcher Elva Escobar Briones.
Life cycle of Capitella sp. in Galveston Bay
Capitellid polychaetes are opportunistic inhabitants of disturbed or polluted sediments. Capitella capitata was considered a cosmopolitan species, but actually comprises many different sibling species which differ genetically and in their life history characteristics. We are studying the life cycle of these worms in Galveston Bay and explore their potential as indicator species for sediment pollution.
Metatrochophore larva of Capitella sp. from Galveston Bay