Eucyclops festivus Lindberg, 1955

Gutierrez-Aguirre, Martha Angelica, Mercado-Salas, Nancy Fabiola & Cervantes-Martinez, Adrian, 2013, Description of Eucyclops tziscao sp. n., E. angeli sp. n., and a new record of E. festivus Lindberg, 1955 (Cyclopoida, Cyclopidae, Eucyclopinae) in Chiapas, Mexico, ZooKeys 351, pp. 1-30 : 14-16

Eucyclops festivus Lindberg, 1955 Figs 10-11

Eucyclops festivus : Lindberg (1955), fig. 2 a–d.

Eucyclops festivus : Suárez-Morales (2004), 617 p.

Eucyclops festivus : Mercado-Salas (2009), table 3, figs 138-139

Eucyclops pectinifer , Gutiérrez-Aguirre and Cervantes-Martínez (2013), table 1. Synonym.

Material examined.

One adult ♀ specimen dissected, mounted in glycerin sealed with Entellan. One adult ♂, dissected, mounted in glycerin sealed with Entellan, and seven adult males undissected, ethanol preserved (90%) with a drop of glycerin, deposited in the senior author’s collection, at Universidad de Quintana Roo, Cozumel. Samples collected at 14. April. 2000 by A. Cervantes-Martínez, M. A. Gutiérrez-Aguirre and M. Elías-Gutiérrez in pond 3 to Laguna Montebello, Chiapas, México (16°06'42"N, 91°41'32"W). At sampling the maximum depth was 0.2 m; the water temperature 24°C and the dissolved oxygen 6.8 mg L-1.

Remarks.

Eucyclops festivus has been recorded in North and Central Mexico ( Suárez-Morales and Reid 1998, Mercado-Salas 2009). This is the southernmost record of the species in the country. Specimens from Chiapas were assigned to Eucyclops festivus because all the morphological characters, even the meristic features observed in the specimens from Chiapas are similar to those in the original description: in females and males the inner spine of fifth leg is 1.7-1.8 times longer than outermost seta, and the median seta is 1.5 times longer than the inner spine (Fig. 10A, B, D). The Fu length/width ratio is between 5-6 in the females, with spinules along the entire outer margin, and naked along inner margin (Fig. 10B, C). Caudal rami parallel in the male (Fig. 10D, E). The length ratio of innermost caudal seta (VI)/outermost terminal caudal seta (III) is 1.24 ± 1.6 (Fig. 10C, E).

The antennal basis is adorned with the spinule groups N1, N2, N3, N4, N5, N6, and N17 on the frontal surface; whereas the groups N7, N8, N10, N11, N12, N13, N 14, N15, and N16 are present on the caudal surface in female and male (Fig. 11 A–D). Distal margin of the intercoxal sclerites in P1-P4 bear fine hair-setae (Fig. 11 E–G). The length/width ratio of Enp3P4 is 2.2, the inner spine is 1.21 times longer than the segment, and the inner margin of BspP4 is naked in female (Fig. 11F).

Based on the presence of the group N6 on the frontal surface of antennal basis, the naked inner margin of BspP4, the long caudal rami, and the serrated hyaline membrane on the three distalmost segments of A1 in females, Eucyclops festivus is not included in the serrulatus-group.