Phylum Arthropoda
Subphylum Crustacea
Class Eumalacostraca
Order Isopoda
Family Cirolanidae

Metacirolana mayana (Bowman, 1987)


Synonyms: Bahalana mayana Bowman, 1987

	Metacirolana mayana

Taxonomic Characterization: Medium-sized cirolanid isopod without eyes and pigment. Distinguished from its congeners by the acutely produced clypeus, the long segment 2 of antenna 1, the fewer flagellar segments in antenna 1 and 2, the long subapical seta on the mandibular palp segment 2, the short segment 4 of the maxillipedal palp, the morphology of pereopods 1-3, and the narrow exopod of the uropod (Bowman, 1987). Botosaneanu & Iliffe (1997:93) stated that Bahalana mayana should be removed from that genus, but a better generic placement was not suggested. As cited by Botosaneanu & Iliffe (1997:93), Dr. N.L. Bruce (in litt., 21 April 1997) believes that this species is "a straight forward eyeless Metacirolana have all of the characters of that genus". B. mayan was transferred to the genus Metacirolana Nierstrasz, 1931 by Botosaneanu & Iliffe (2002:101-103).  They further note that the robust pereiopod IV is intermediary between the strongly raptoral PI-PII and the ambulatory PV-PVII.  Apex masculina has a characteristic shape in contrast with the extremely simple one found in most stygobitic Cirolanidae.

Ecological Classification: Stygobitic

Size: Adult males range in length from 4.5-10.0 mm; adult females from 7.9-8.5 mm.

Number of Species in Genus: At least 30 mostly marine, epigean species but only two species are stygobitic.

Genus Range of stygobitic Metacirolana:

Species Range: Originally described from Cueva Quebrada, Isla Cozumel and Temple of Doom Cave, near Tulum on the mainland of the Yucatan Peninsula, Mexico by Bowman, 1987.  Additional material reported by Botosaneanu & Iliffe (2002, in prep.) came from Cenote Aayin Aak (also known as Cenote Crustacea), Puerto Morales, Cenote Chac Mool, Puerto Aventuras and Cenote 27 Steps, Akumal on the mainland, and Cenote Tres Potrillos and Cenote Aerolito on Isla Cozumel.

Closest Related Species: The only other stygobitic species in the genus is Metacirolana ponsi collected from an anchialine cave lake on Cabrera, Balearic Islands, Spain.

Habitat: Anchialine limestone caves

Ecology: In Cueva Quebrada, specimens were collected approximately 800 m from the entrance at a depth of about 5 m. Salinity at this point was 21 ppt and dissolved oxygen, 3.0 ppm. Specimens in Temple of Doom Cave were collected in 12 to 18 m depths, from water of 14 ppt salinity (Bowman, 1987).

Life History: Collected specimens include 9 males, 6 females and 1 juvenile (Bowman, 1987). Additional material reported by Botosaneanu & Iliffe (2002), included 3 males, 8 females and 3 juveniles.

Evolutionary Origins: The case of two described stygobitic species of Metacirolana is one of the very few enabling sound speculation about the question: what was the appearance of the marine ancestors of present-day subterranean-adapted Cirolanidae?

Conservation Status: Restricted to anchialine caves, both on Isla Cozumel and on the Caribbean coastline of the Yucatan Peninsula mainland .

References:

Links: