With the advent of PCR [1] and cheap sequencing techniques [2], molecular phylogenetic investigations have been the most important source of phylogenetic data and an important touchstone for morphology based taxonomies.
This, and the many features in larval morphology, bodes well for a future phylogenetically based taxonomy of the group.
The base taxonomy is an empirically based taxonomy, i.e. it was designed based on existing literature and also on the knowledge of several experts.
We provide component based taxonomy of energy efficient techniques in Table 1.
In traditional morphology-based taxonomy, morphologically discrete forms are tentatively recognized and hypothesized to be species.
A DNA barcode can overcome several limitations of morphology-based taxonomy, including detection of morphologically cryptic species, recognition of species with high phenotypic plasticity, and individuals in early ontogenetic stages or incomplete and poorly developed specimens (Valentini et al. 2008).
Traditional morphology-based taxonomy, is only one way to describe "life's diversity" and species hypotheses developed based on morphology alone should be tested using different approaches with a variety of data sets [ 8].
We speculate that such cryptic diversity results from the generally low dispersal capabilities of many mastacembelids, combined with an apparent paucity of qualitative morphological characteristics in this group, which may hinder accurate morphology-based taxonomy and species diagnosis in some instances.
An additional complication for morphology-based taxonomy is the difference between castes within the same species, e.g. males, major and minor workers, and queens.
Such phenotypic diversity has made it particularly difficult to delineate species and morphology-based taxonomy is very confusing in this genus.
