January 27, 2015 supplementary class II

Species (again): linking it all together


Introduction: What is a species?
Biological species: Fish species complex
OTU & barcodes: ARMS and estimating coral reef biodiversity.

Part 1: Introduction: What is a species?

A species can be different, depending on who you talk to, or what meaning is implied.

Before we discuss species, we must be clear about what species concept we are discussing.

Three types are:

A. taxonomic species

B. biological species

C. OTU/barcode species

Taxonomic species

A species with a scientific name.

Names are important for science & conservation.

Accuracy and authorship important

Problems:

Naming species takes time & money.

Few experts.

Biological species

A species proven to reproduce only with itself.

Reproductive isolation.

Species concept important.

Problems:

Experiments take time & money.

Hybrids? Evolution is messy.

OTU/barcode species

A species defined by genetic differences.

Implies a threshold value.

Quick and easy.

Problems:

Sequencing species takes time & money.

Limited by previous knowledge.

Not always “true”, barcoding gap is problematic.

Part 2: Biological species

Fish species complex in the Pacific (Leray et al. 2010)

This study deals with:

Biological species

Can be detected through observation of reproduction.

Also, reproductive experiments.

But these require extensive field work. Recently, molecular analyses usual, using phylogeny.

Background: Genus Dascyllus

Complex has 4 species:

D. trimaculatus (E. Africa to Central Pacific): 3 spots

D. albisella (Hawaii): white flanks

D. strasburgi (Marquesas Islands): gray

D. auripinnis (Line, Phoenix Islands): yellow fins

Each species has its own ecology and preferred habitats. Figure from Leray et al. 2010.

Specimens (n=563) from across the Indo-Pacific.

Microsatellite DNA data examined (data from previous research included).

Phylogenetic analyses and genotype assignment.

From Leray et al. (2010).

Previous research showed 5 clades, not 4 (Bernadi et al. 2003).

This research showed 7 (!) groups of Dascyllus, not all with clear morphology.

Appears ancient history of Indo-Pacific combined with recent evolutionary events drives speciation.
Hybridization appears to be occurring.
NOTE: unknown species are not yet valid species, or new species. They are undescribed species.

Summary: Using biological species data, we can now go and revise taxonomic species.

Biological species
Results could lead to “finding” undescribed species or groups

This leads to....

Taxonomic species

Describing a species.

Only way to give a scientific name.

New species.

Part 3: OTU/barcode species

ARMS and crustaceans

Plaisance et al. 2011;

Brainard et al. 2010

ARMS = Autonomous Reef Monitoring Systems.

Built cheaply, mass produced. In the image of dead coral head. Can use to estimate total biodiversity of a reef.

Hand picking larger specimens + DNA barcoding of all things!

Can estimate how well biodiversity is being found by a saturation curve.

OTU/barcode species

Results could lead to “finding” undescribed species or groups

This leads to...

Biological species

Results could lead to “finding” undescribed species or groups

This leads to....

Taxonomic species

Describing a species.

Only way to give a scientific name.

New species.