Paracyclops poppei (Rehberg)

Mercado-Salas, Nancy & Suárez-Morales, Eduardo, 2009, A new species and illustrated records of Paracyclops Claus, 1893 (Copepoda: Cyclopoida: Cyclopinae) from Mexico, Journal of Natural History 43 (45 - 46), pp. 2789-2808 : 2804-2805

Paracyclops poppei (Rehberg)

( Figures 8 , 9 )

Material examined

Two adult female specimens from water reservoir in San Miguel de los Sandoval, El Llano, (21°53′10.66′′ N, 102°06′26.69′′ W), state of Aguascalientes, central Mexico, altitude 1998 m, coll. Marcelo Silva-Briano, 13 October 1991. One specimen dissected, slide in collection of Zooplankton at ECOSUR-Chetumal (ECO-CHZ-03988). One specimen in vial, ethanol-preserved (ECO-CHZ-03988) .

Remarks

The morphology of the specimens examined agrees in most respects with the descriptive study of the species by Karaytug (1999). There are, however, some characters that reflect some of the morphological variability described by Karaytug (1999). In the Mexican specimens examined, the length: width ratio of the caudal rami is 5.0, versus 3.6 in European specimens; Karaytug and Boxshall (1999) recognized that the range of variation of the length of the caudal rami is greater in American specimens (2.1–3.9); however, the proportions of these Mexican specimens allows a considerable expansion of this range. Caudal seta II (sensu Karaytug 1999, arrowed in Figure 8D ) is also longer than in the European forms (as illustrated by Karaytug 1999). The exopodal spines and the terminal endopodal spine of leg 1 ( Figure 9A ) are relatively longer in the Mexican females of P. poppei than in the depictions by Karaytug and Boxshall (1998b). The ornamentation of the coxa of leg 4 is heavier in the European specimens than in the Mexican ones ( Figure 9D ). The inner spine of the terminal endopodal segment of leg 4 is relatively longer in the Mexican specimens (1.74 versus 1.30 times as long as segment).

Paracyclops poppei is a very common and widespread species in North America (Karaytug 1999), but in Mexico it has been reported from only two sites in central Mexico ( Suárez-Morales and Reid 1998), including Aguascalientes ( Dodson and Silva-Briano 1996).

Figures

Figure 8. Paracyclops poppei, adult female from Aguascalientes, Mexico. (A) Antennule; (B) antenna; (C) urosome, ventral view; (D) same, dorsal view. Scales A–D, 50 µm.

Figure 9. Paracyclops poppei, adult female from Aguascalientes, Mexico. (A) Leg 1; (B) leg 2 with separated endopod and exopod; (C) leg 3; (D) leg 4 with separated endopod. Scales A–D, 50 µm.