Background
Phylum Porifera includes ∼8,500 valid species distributed world-wide in aquatic ecosystems ranging from ephemeral fresh-water bodies to coastal environments and the deep-sea. The taxonomy and systematics of sponges is complicated, and morphological identification can be both time consuming and erroneous due to phenotypic convergence and secondary losses, etc. DNA barcoding can provide sponge biologists with a simple and rapid method for the identification of samples of unknown taxonomic membership. The Sponge Barcoding Project (
www.spongebarcoding.org
), the first initiative to barcode a non-bilaterian metazoan phylum, aims to provide a comprehensive DNA barcode database for Phylum Porifera.
Methodology/Principal Findings
∼7,400 sponge specimens have been extracted, and amplification of the standard COI barcoding fragment has been attempted for approximately 3,300 museum samples with ∼25% mean amplification success. Based on this comprehensive sampling, we present the first report on the workflow and progress of the sponge barcoding project, and discuss some common pitfalls inherent to the barcoding of sponges.
Conclusion
A DNA-barcoding workflow capable of processing potentially large sponge collections has been developed and is routinely used for the Sponge Barcoding Project with success. Sponge specific problems such as the frequent co-amplification of non-target organisms have been detected and potential solutions are currently under development. The initial success of this innovative project have already demonstrated considerable refinement of sponge systematics, evaluating morphometric character importance, geographic phenotypic variability, and the utility of the standard barcoding fragment for Porifera (despite its conserved evolution within this basal metazoan phylum).
Abstract. The accurate and precise reconstruction of Quaternary
climate as well as the events that punctuate it is an important driver of the study
of lake sediment archives. However, until recently lake sediment-based
palaeoclimate reconstructions have largely concentrated on Northern
Hemisphere lake sequences due to a scarcity of continuous and
high-resolution lake sediment sequences from the Southern Hemisphere,
especially from the southern mid-latitudes. In this context, the deep maar
lakes of the Auckland Volcanic Field of northern New Zealand are significant
as several contain continuous and well-laminated sediment sequences. Onepoto
Basin potentially contains the longest temporal lake sediment record from
the Auckland Volcanic Field (AVF), spanning from Marine Isotope Stage 6e (MIS 6e) to the early Holocene when lacustrine
sedimentation was terminated by marine breach of the south-western crater
tuff ring associated with post-glacial sea-level rise. The Onepoto record
consists of two new, overlapping cores spanning ca. 73 m combined with
archive material in a complete composite stratigraphy. Tephrochronology and
14C dating provide the fundamental chronological framework for the core,
with magnetic relative palaeo-intensity variability downcore, and meteoric
10Be influx into the palaeolake to refine the chronology. The µ-XRF (micro X-ray fluorescence)
downcore variability for the entirety of the lake sediment sequence has
been established with measurement of a range of proxies for climate
currently underway. This work will produce the first continuous record of
the last 200 kyr of palaeoclimate from northern New Zealand to date.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.