http://www.collembola.org/key/paraxeny.htm - Last updated on 2010.03.03 by Frans Janssens
Checklist of the Collembola: Key to the species of Paraxenylla

This key is still under construction. Note that missing figures will be provided as soon as possible. Currently, the key is in the feasibility study phase to find out how to integrate in the checklist in a modular way a key that has been generated with DELTA.

José G. Palacios-Vargas, Laboratorio de Ecologia y Sistemática de Microartrópodos, Departamento de Biologia, Facultad de Ciensas, Universidad Nacional Autónoma de México, México D.F.
Frans Janssens, Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium

Rationale

The rationale for taxa used and not used as well as subtaxonomic classification for some taxa is to be provided.

Key

Note that no distinction between subtaxa and taxa is made in the key. 

1(0). Ventral tube with 1 + 1 setae................................. 2
      Ventral tube with more than 1 + 1 setae....................... 6
 
2(1). Tenaculum with 2 teeth on each ramus; tibiotarsi without tenent
        hairs.................................................. cubana
      Tenaculum with 3 teeth on each ramus; tibiotarsi with tenent
        hairs....................................................... 3
 
3(2). Second abdominal segment with 1 + 1 ventral setae............. 4
      Second abdominal segment with more than 1 + 1 ventral setae... 5
 
4(3). Body length about 1 mm; antennal sensilla only one smaller than
        others............................................... lapazana
      Body length less than 0.5 mm; antennal sensilla two bigger than
        others................................................. piloua
 
5(3). Second abdominal segment with 1 + 1 ventral setae; body length
        about 0.9 mm; tibiotarsus with a total of 7 tenent hairs;
        unguis with one teeth............................ affiniformis
      Second abdominal segment with 3 + 3 ventral setae; body length
        about 1.5 mm; tibiotarsus with only 4 tenent hairs; unguis
        with no teeth....................................... peruensis
 
6(1). Ventral tube with 2 + 2 setae............................ mangle
      Ventral tube with more than 2 + 2 setae....................... 7
 
7(6). Ventral tube with 3 + 3 setae........................... arenosa
      Ventral tube with 4 + 4 setae................................. 8
 
8(7). Dens confluent with mucro; mucro extremely acuminate and pointed
        on apex.............................................. oceanica
      Dens separated from mucro; mucro curved, with distinct dorsal
        lamella............................................. norvegica

Differential diagnoses

affiniformis
Body length about 0.9 mm. Second abdominal segment with more than 1 + 1 ventral setae. Second abdominal segment with 1 + 1 ventral setae. Tenaculum with 3 teeth on each ramus. Tibiotarsi with tenent hairs. Tibiotarsus with a total of 7 tenent hairs. Unguis with one teeth. Ventral tube with 1 + 1 setae.

arenosa
Ventral tube with more than 1 + 1 setae. Ventral tube with more than 2 + 2 setae. Ventral tube with 3 + 3 setae.

cubana
Tenaculum with 2 teeth on each ramus. Tibiotarsi without tenent hairs. Ventral tube with 1 + 1 setae.

lapazana
Antennal sensilla only one smaller than others. Body length about 1 mm. Second abdominal segment with 1 + 1 ventral setae. Tenaculum with 3 teeth on each ramus. Tibiotarsi with tenent hairs. Ventral tube with 1 + 1 setae.

mangle
Ventral tube with more than 1 + 1 setae. Ventral tube with 2 + 2 setae.

norvegica
Dens separated from mucro. Mucro curved, with distinct dorsal lamella. Ventral tube with more than 1 + 1 setae. Ventral tube with more than 2 + 2 setae. Ventral tube with 4 + 4 setae.

oceanica
Dens confluent with mucro. Mucro extremely acuminate and pointed on apex. Ventral tube with more than 1 + 1 setae. Ventral tube with more than 2 + 2 setae. Ventral tube with 4 + 4 setae.

peruensis
Body length about 1.5 mm. Second abdominal segment with more than 1 + 1 ventral setae. Second abdominal segment with 3 + 3 ventral setae. Tenaculum with 3 teeth on each ramus. Tibiotarsi with tenent hairs. Tibiotarsus with only 4 tenent hairs. Unguis with no teeth. Ventral tube with 1 + 1 setae.

piloua
Antennal sensilla two bigger than others. Body length less than 0.5 mm. Second abdominal segment with 1 + 1 ventral setae. Tenaculum with 3 teeth on each ramus. Tibiotarsi with tenent hairs. Ventral tube with 1 + 1 setae.

References