Tuesday, March 12, 2013

A new fish - an old problem

The genus Alburnoides belongs the large carp family Cyprinidae that includes freshwater fishes such as he carps, the minnows, and their relatives. This is the largest fish family, and more notably the largest family of vertebrate animals, with over 2,400 species. Cyprinids are highly important food fish because they make the largest part of biomass in most water types except for fast-flowing rivers.

X-Ray for Alburnoides manyasensis
The genus Alburnoides is widely distributed in Turkey in rivers and streams of basins of the Marmara, Black and Aegean seas, being absent only from the Mediterranean Sea basin. Now, a new species Alburnoides manyasensis, is described from the Koca Stream drainage of Lake Manyas, Marmara Sea basin in Anatolia and it is currently only associated with this specific locality. The name of the species is an adjective that is derived from the name of Lake Manyas to which the new species is possibly endemic.

The new species inhabits clear fast running water with cobble and pebble substrates. It is a comparatively small representative of the family with maximum known body length of only 92 cm while the largest representative of the family, the giant barb (Catlocarpio siamensis) can reach up to 3 m in length.

A quick look at BOLD showed me that 36 barcode sequences of the genus Alburnoides are in the database but only 18 are public. Most of them have been identified as Alburnoides bipunctatus but a quick NJ tree of the public sequences showed three clades separated by relatively deep divergence. That could be an indication of species but without a closer look at actual specimens and more information I will refrain from jumping to any conclusion. However, if there are several species hiding under one name it would be very important to find out if they are already known to science or not. This is of course only possible if the DNA Barcode library is complete.

Localities for barcoded specimens of the genus Alburnoides
When I read all these new species records I always wonder why in most cases such as for Alburnoides manyasensis they are not assigned a DNA Barcode as soon as they are described. I am well aware that not everybody has access to a sequencing facility and that there probably aren't sufficient funds to do that but it would at least be a goal worth aiming for. An initiative to generate DNA Barcodes for all species described in the years to come. It would need money but who says that there aren't any potential funders that like the idea. However, it would also need the taxonomic community to provide smallest tissue bits from their type material. That is probably far more complicated to accomplish although no voucher would be damaged. It still seems to be very hard for some taxonomists to share a piece of a specimen especially with the DNA guys.

At this point the researchers who described Alburnoides manyasensis assume that it potentially represents an endemic species. Maybe it is not and we might even have some barcoded specimens registered under a different in this case wrong name. I am afraid we might not be able to find out as it is still common practice in many collections to preserve specimens in formalin. The type specimen (and the paratypes) might be already lost for any DNA-based research.

No comments:

Post a Comment