Zoological Studies

Vol. 51 No. 6, 2012

On Some Caligids (Copepoda: Caligidae) from Plankton of a Coastal Lagoon in the Gulf of Mexico with a Description of a New Species of Metacaligus

Eduardo Suárez-Morales1,*, Il-Hoi Kim2, and Benigno J. Escamilla3

1El Colegio de la Frontera Sur (ECOSUR), Chetumal, Quintana Roo 77014, Mexico
2Department of Biology, Kangreung National University, Kangreung, Kangwon do 210 702, South Korea
3Instituto Tecnológico de Mérida. Av. Tecnológico s/n, Mérida Yucatán 97118, Mexico

Eduardo Suárez-Morales, Il-Hoi Kim, and Benigno J. Escamilla (2012) A collection of zooplankton from a coastal system of the southern Gulf of Mexico contained several caligid copepods that were taxonomically examined.  The following species were identified: Caligus rufimaculatus Wilson, 1905, C. undulatus Shen and Li, 1959, Caligus sp., Metacaligus rufus (Wilson, 1908), and an undescribed species of Metacaligus Thomsen, 1949.  The 1st species (C. rufimaculatus) was previously reported and redescribed from specimens collected in this system.  Caligus undulatus is known only from plankton surveys; our specimens show subtle differences with respect to other known populations.  Metacaligus rufus is redescribed based on adult male and female specimens collected from Chelem; this species has not been redescribed since its original description.  Both C. undulatus and M. rufus represent new geographic records in the Gulf of Mexico and the Northwestern Tropical Atlantic region.  Metacaligus yucatanensis sp. nov. is described based on male individuals and a single female with a unique combination of characters including: 1) leg 1 with all elements of the distal segment inserted on the inner margin, and 2) the absence of an outer spine on the 2nd exopodal segment of the 2nd leg.  This is the 5th species of the genus currently known. 

Key words: Planktonic crustaceans, Parasitic copepods, Plankton ecology, Zooplankton, Invertebrate taxonomy.

*Correspondence: E-mail:esuarez@ecosur.mx