Coded Taxonomic Description
The Order Symphypleona Börner, 1901 shows some ambiguity in current morphological methods, particularly when describing the head and body chaetotaxy (Betsch 1997, Betsch & Waller 1994, Bretfeld 1990, 1999, Christiansen & Bellinger 1998). The Order is composed by springtails with globular body shape, as result of modification and fusion of thoracic and abdominal segments I-IV, this condition hinders the direct assignment of segments identity.
An approach that can reduce the ambiguity of the taxonomic descriptions, is the description of body parts into coded morphological units, straightforwardly representing the actual body segments and appendicular whorls (Hopkin 1997, Jura et al., 1987, Nayrolles 1988, 1990a, 1990b, 1991, Tomizuka & Machida 2015), in such a way that any species can be compared from the coded data base. This is in replacement to the traditional descriptive text, many times with ambiguous terminology, and often applying different and not directly comparable chaetotaxic systems. The coded notation method would lead to a more comprehensive analysis of the chaetotaxy, as well as a direct availability of the data for comparative studies. Furthermore, a coded description can easily be amended, molecular data can be added in the character list and matrix, and new complementary morphological features can be inserted as new information is available.
The qualitative description of the shape and size of the different chaeta is also subject to a great deal of ambiguity and poor definition, the adjectives are not standard and the very definition of what is a macro, meso or microchaeta is not always clear. Therefore, a bank of shapes with high quality images is imperative to discard all the subjective descriptions. There are several chaetae banks published for different groups of Collembola, including some with precise line drawings(Betsch 1980, Christiansen 1966, Deharveng 1983, Nayrolles 1991), and some with SEM photography(Cipola et al., 2020, de Lima et al., 2022, Lukić et al., 2010, Zeppelini et al., 2022, Zhang & Deharveng 2015), it is a matter of time to have a fully reliable chaetal shapes collection, so a specific chaeta can be addressed directly by its reference in the bank, in the coded description.
A standard, fully coded method for species description may be an improvement to the traditional descriptive text, it may allow to use machine learning and high-quality imaging to enhance the efficiency of species descriptions and diversity recognition, offering a powerful tool to understanding of global processes, and face the diversity decline.