52
G. Rodriguez
shore together with Danax denticulatus, Oliva caribacensis, and the anomuran crustacean Lepidapa.
Inside Tablazo Bay, euryhaline forms progressively displace marine elements of the gulf. The west coast of the bay, the strait, and the northern
shores of the lake are occupied by halophytic vegetation typical of littoral
dunes and by scarce mangrove growth. In general, these shores have a poor
invertebrate fauna. The upper intertidal is inhabited by the fiddler crab
Uca leptadactyla, while an association of the abundant brackish water
clams Palymesada salida, Ruppia maritima, Uca maracaani, and Callinectes sapidus occupies the lower intertidal. Encrusting gastropods (Littarina
nebulosa, Thais aemastoma flaridana) are typical on the trunks of occasional mangrove trees. Muddy shores with dense mangroves (Rhizaphora
mangle) along the eastern shore of the bay and in the lower Limon River
tend to be void of halophytic vegetation. Intertidal organisms, like Balanus,
the gastropod Neritina reclivata, and the red alga Calaglassa leprieurii are
abundant on the trunks of mangroves, while the mud crab Rhithrapanopeus harrisii and mangrove crabs (Metasesarma rubripes, Aratus pisanii)
occur among the branches. The invertebrate fauna of muddy intertidal
bottoms is comprised of the pulmonate gastropod Melampus coffeus and
high densities of fiddler crabs (Uca cumulanta with 330 burrows m- 2 and
Uca rapax with 113 burrows m- 2 ) and the swamp ghost crab Ucides cordatus (10 burrows m- 2 ). In coarser sediments, Uca rapax is substituted by Uca
leptadactyla (85 burrows m- 2 ; Rodriguez 1973). The ubiquitous clam Polymesoda salida is also present in the sublittoral of densely forested shores.
The seagrass Ruppia maritima covers lower intertidal bottoms and Palymesoda salida and the blue crab Callinectes sapidus are abundant components in the submersed meadows. Well-developed mangrove stands are
only found on the northeastern shore of Maracaibo Lake and north and
south of the Catatumbo River (E. Medina, pers. comm.). Intertidal invertebrates of oligohaline waters, like the freshwater sponge Spangilla aspinasa,
the gastropod Neritina reclivata, and the mangrove crab Metasesarma
rubripes, settle on artificial peers and platforms and on rare natural hard
substrates.
The sublittoral community of the Maracaibo System is not well known;
however, the fact that 165 species of mollusks have been recorded suggests
a rich and diverse subtidal fauna. Dominant components of the lower subtidal community are the mytilid pelecypod Mytella maracaibaensis (up to
158 g dry weight m- 2 ), the tubicolous amphipod Coraphium rioplatense,
and polychaetes, like Heteramastus filifarmis (980 ind. m- 2 ), Sigambra sp.
(1,380 ind. m- 2 ), Streblaspia sp. ( 4,000 ind. m- 2 ), Capitella capitata
( 160 in d. m- 2 ), and Nereis succinea (360 in d. m- 2 ). The density of polychaetes has decreased during the last decade (Morales 1987), partly due to sub-
G. Rodriguez
shore together with Danax denticulatus, Oliva caribacensis, and the anomuran crustacean Lepidapa.
Inside Tablazo Bay, euryhaline forms progressively displace marine elements of the gulf. The west coast of the bay, the strait, and the northern
shores of the lake are occupied by halophytic vegetation typical of littoral
dunes and by scarce mangrove growth. In general, these shores have a poor
invertebrate fauna. The upper intertidal is inhabited by the fiddler crab
Uca leptadactyla, while an association of the abundant brackish water
clams Palymesada salida, Ruppia maritima, Uca maracaani, and Callinectes sapidus occupies the lower intertidal. Encrusting gastropods (Littarina
nebulosa, Thais aemastoma flaridana) are typical on the trunks of occasional mangrove trees. Muddy shores with dense mangroves (Rhizaphora
mangle) along the eastern shore of the bay and in the lower Limon River
tend to be void of halophytic vegetation. Intertidal organisms, like Balanus,
the gastropod Neritina reclivata, and the red alga Calaglassa leprieurii are
abundant on the trunks of mangroves, while the mud crab Rhithrapanopeus harrisii and mangrove crabs (Metasesarma rubripes, Aratus pisanii)
occur among the branches. The invertebrate fauna of muddy intertidal
bottoms is comprised of the pulmonate gastropod Melampus coffeus and
high densities of fiddler crabs (Uca cumulanta with 330 burrows m- 2 and
Uca rapax with 113 burrows m- 2 ) and the swamp ghost crab Ucides cordatus (10 burrows m- 2 ). In coarser sediments, Uca rapax is substituted by Uca
leptadactyla (85 burrows m- 2 ; Rodriguez 1973). The ubiquitous clam Polymesoda salida is also present in the sublittoral of densely forested shores.
The seagrass Ruppia maritima covers lower intertidal bottoms and Palymesoda salida and the blue crab Callinectes sapidus are abundant components in the submersed meadows. Well-developed mangrove stands are
only found on the northeastern shore of Maracaibo Lake and north and
south of the Catatumbo River (E. Medina, pers. comm.). Intertidal invertebrates of oligohaline waters, like the freshwater sponge Spangilla aspinasa,
the gastropod Neritina reclivata, and the mangrove crab Metasesarma
rubripes, settle on artificial peers and platforms and on rare natural hard
substrates.
The sublittoral community of the Maracaibo System is not well known;
however, the fact that 165 species of mollusks have been recorded suggests
a rich and diverse subtidal fauna. Dominant components of the lower subtidal community are the mytilid pelecypod Mytella maracaibaensis (up to
158 g dry weight m- 2 ), the tubicolous amphipod Coraphium rioplatense,
and polychaetes, like Heteramastus filifarmis (980 ind. m- 2 ), Sigambra sp.
(1,380 ind. m- 2 ), Streblaspia sp. ( 4,000 ind. m- 2 ), Capitella capitata
( 160 in d. m- 2 ), and Nereis succinea (360 in d. m- 2 ). The density of polychaetes has decreased during the last decade (Morales 1987), partly due to sub-