Boundaries

This ecoregion encompasses the island of Cuba, a chain of islands located to the south of Cuba known as the Archipelago de los Canarreos, and the Cayman Islands.  The largest of the islands in the Canarreos Archipelago is la Isla de Juventud, located southeast of Cuba.  The Cayman Islands consist of three islands: Grand Cayman, Cayman Brac, and Little Cayman.

Topography

The topography of Cuba varies dramatically, consisting of mountains and hills, plains and valleys, forests and beaches, and low plateaus.  There are three main mountain chains: the Sierra Maestre on the eastern part of the island, which contains the Pico Turquino, Cuba’s highest peak at 1,975 m; the Sierra del Escambre along the eastern shore; and the Cordillera de Guaniguanico along the western shore.  The Cordillera de Guaniguanico is divided into two regions: the Sierra de los Órganos in the west is characterized by steep, flat-topped mountains, and the Sierra del Rosario in the east is comprised of limestone and igneous rock (Baker 2006).   Seventy percent of Cuba’s area has limestone geology.  The island’s location near the equator has aided in the creation of conical-hill karst features known as mogotes, loaf-shaped mountains of limestone worn away by seeping water.   There are also many conical hillocks in the karstic depression of the Valle de Viñales in Cuba’s northeast, which was designated a UNESCO World Heritage Site in 1999 (Baker 2006).  The Cayman Islands are comprised of limestone of low elevation and support evergreen thicket and seasonal swamp (Brunt 1994).  Grand Cayman is the largest of the three islands at 53 km in length and 14 km wide, and Cayman Brac is the highest, with an elevation on 43 m.  The smallest island, Little Cayman, is a mere 12 m above sea level, and is 14 km long (WWF 2001).

Freshwater habitats

Cuba’s flowing waters originate in the island’s high mountains and descend across its rolling plains.   During the dry season, the surface waters dwindle and disconnect, later swelling and flooding in the wet season, during which 80 percent of the annual rainfall occurs (Baker 2006).  To prevent destruction from flooding, several reservoirs were built to control fluctuations in river flow.  Ten miles west of the Valle de Viñales is the Gran Caverna de Santo Tomás, which begins more than 29 miles of unconnected limestone caves.  These caves of Cuba provide anchialine habitats, which have restricted exposure to open air and are home to a rich fauna.  The caves have both fresh water, which occurs at surface depths, and sea water, which mixes at lower depths.  In the Cayman Islands, most wetlands are brackish or saline with about fifty percent by area comprised of mangrove swamps.  Grand Cayman has the largest inland mangroves in the Caribbean, as well as several other notable wetlands such as Malportas Pond, Head of Barkers, and South Sound swamp (Proctor and Fleming 1999).

Terrestrial habitats

Mountainous regions are located in the east, west and central regions of Cuba and comprise approximately 18 percent of the landscape.  In the low-lying areas of central Cuba, semi-deciduous woodlands and rainforests as well as savannah vegetation and coastal and upland scrub can be found, comprising approximately seventy-five percent of the landscape (Cameron 1998). The three Cayman Islands are comprised of mangrove swamp formations and dry evergreen woodlands, occupying the limestone and dolomite karst terrain above sea level (Procter and Flemming 1999). 

Description of endemic fishes

Of the many species apparently restricted to this ecoregion, one of particular interest is Atractosteus tristoechus, the rare Cuban gar, a living fossil found in western Cuba and Isla de la Juventud.  Other fishes endemic to Cuba are Nandopsis tetracanthus, located throughout Cuba, and Cichlasoma ramsdeni, which is confined to eastern Cuba (Rauchenberger 1988).  In the Cayman Islands there are two endemic species of fish, Gambusia xanthosoma and Limia caymanensis, both of which are located in Grand Cayman (Rivas 1986).

Other noteworthy fishes

Sicydium plumieriis an amphidromous Gobiidae species that spawns in fresh waters, undergoes a planktonic phase in marine waters, and later returns to the rivers to grow and reproduce.  The juveniles of this species are strong swimmers and possess well-developed fins and pelvic suction cups that allow them to climb major waterfalls and reach the upper regions of river catchments quickly (Keith 2003). Also noteworthy is Rivulus marmoratus, a unique hermaphroditic species of fish found throughout the ecoregion in mangrove habitats (Murphy & Collier 1996).

Justification for delineation

Ecoregion delineations for the Caribbean islands follows Olson et al. (1998) with one exception: the Cayman Islands and Cuba have now been merged based on biogeographic work by Rauchenberger that shows relationships between Cayman fishes and those of eastern Cuba (1988).  Rauchenberger (1988) also suggests that eastern Cuba might be distinct from the rest of that island.  That division is not represented in this delineation, but future research may suggest such a revision.   La Isla de Juventud fauna are most closely associated with species found in the western regions of Cuba, due to Pliocene land connections (Rauchenberger 1988). 

Level of taxonomic exploration

Good