Phylum Arthropoda
Subphylum Crustacea
Class Malacostraca
Order Amphipoda
Family Hadziidae

Mayaweckelia cenoticola Holsinger, 1977

	Mayaweckelia cenoticola: after Holsinger, 1977

Taxonomic Characterization: Small to medium-sized amphipod without eyes or pigment. Antenna 1 is as long or slightly longer than the body. Distal 10-12 flagellar segments of antenna 1 with aesthetascs (1 each); pereopod 6 up to 15% longer than pereopod 7; dactyls of pereopods 5-7 with row of fine setae (pubescence) on distal half of upper margin and 2 sets of setae each on lower margin (Holsinger, 1990). Characterized by the absence of mandibular palps and a second (terminal) segment on the outer ramus of uropod 3. Lacks basofacial spines on uropod 1.

Disposition of Specimen: National Museum of Natural History, Smithsonian Institution, catalog numbers USNM 151181; Museum of Texas Tech University; and the private collection of John Holsinger.

Ecological Classification: Stygobitic

Size: Adult males are up to 4.0 mm in length, while largest adult females are 6.0 mm

Number of Species in Genus: Two, both stygobitic.

Genus Range:

Species Range: Recorded in many caves in Yucatan, Campeche and Quintana Roo. Collection sites in Quintana Roo included: Carwash Cenote, Cenote de San Martin, Cueva de Tancah, Cenote de Las Ruinas, and Cenote de Santa Domingo (Holsinger, 1990); Yucatan sites include Cenote Xtacagiha and Cueva de Orizaba. Rocha et al., 2000 reported M. cenoticola from Grutas de Santa Maria and Grutas de Tzab-Nah, both in Yucatan.

Closest Related Species: Mayaweckelia cenoticola closely resembles M. yucatanensis, known from a single cave in the state of Campeche.

Habitat: Freshwater and anchialine limestone caves

Ecology: Mayaweckelia is predominantly a freshwater inhabitant, and only three of its eleven known populations are recorded from cave waters that are, at most, slightly brackish. In Carwash Cenote, it was found with Tuluweckelia cernua. Initial collections came from small pools isolated from water bodies in the caves (Holsinger, 1977).

Life History: A strongly skewed sexual ratio favoring females may be present for this species.

Evolutionary Origins: Mayaweckelia is related to both Mexiweckelia and Hadzia but differs from these genera in several important ways. It has taxonomic affinities with marine forms and inhabits caves situated between the Pliocene and Pleistocene shorelines of Yucatan. Holsinger (1977, 1990) concluded from this that Mayaweckelia originated from a marine ancestor by "stranding" in newly developing freshwater habitats following the regression of sea water during the late Tertiary or early Quaternary times.

Conservation Status: Widely distributed in freshwater and anchialine caves from Yucatan, Quintana Roo and Campeche, Mexico.

References:

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Contributor: John Holsinger, Old Dominion University, Norfolk, VA