11th ICRS Abstract book - Nova Southeastern University

Poster Mini-Symposium 26: Biodiversity and Diversification of Reef Organisms
26.1182
Morphometric Examination Of Corallite And Colony Variability On The
Caribbean Coral montastraea Cavernosa
Hector RUIZ* 1 , Ernesto WEIL 1
1 Marine science, University of Puerto Rico, Mayaguez, Puerto Rico
The genus Montastraea in the Caribbean was thought to be formed by two species,
M.annularis and M. cavernosa. However, recent research has uncovered two more
species in the M. annularis complex, and two different morphologies of M.cavernosa that
commonly co-occur were separated based on polyp size and behavior. A small-polyped
form mostly active during the day (diurnal ecomorph), and a large-polyped form only
active during the night (nocturnal ecomorph). Nevertheless, no specific taxonomic
separation has ever been proposed and most recent studies using this species lumped the
two ecomorphs. In this work, a multivariate approach was used to explore the ecological,
morphological and behavioral differences between the two behavioral ecomorphs of M.
cavernosa proposed. Ecological surveys at four different reef localities of Puerto Rico
showed that the two behavioral ecomorphs were abundant, but with a differential
distribution along the reef profile. Results indicate that 90 % of shallow (6m) M.
cavernosa colonies were of the diurnal ecomorph, and 60% of the deeper water (20 m)
colonies were of the nocturnal ecomorph. High corallite and colony morphometric
variability within each behavioral ecomorph across depth gradients support the idea that
environmental factors might influence their morphology. Significant morphological
differences in 10 micro-morphological characters analyzed in 60 colonies (30 diurnal and
30 nocturnal) from two reefs (Media Luna and Turrumote), and a Stepwise Canonical
Discriminant Function Analysis, which separated two distinct groups (with 94.0% of all
colonies correctly classified), suggest that the two behavioral ecomorphs are two separate
species (sibling species).
26.1183
Sipunculans Bioeroders From Dead Coral Substrate in The Colombian Caribbean
Carlos GÓMEZ SOTO* 1 , Adolfo SANJUAN MUÑOZ 2 , Tatiana RICO BUITRAGO 1 ,
Andrés FRANCO HERRERA 2
1 Universidad Jorge Tadeo Lozano, Bogotá, Colombia, 2 Universidad Jorge Tadeo Lozano,
Santa Marta, Colombia
In the Colombian Caribbean coral reefs have suffered a gradual decline due to natural and
anthrogenic factors leading to a replacement of the living coral tissue coverage and
inducing structural changes in the communities that live associated. Sipunculans are
exclusively marine animals capable of bore into coral skeletons, although they are
important in consolidating the structure and form of modern coral reefs, in the colombian
Caribbean have been poorly studied. For this reason the present study evaluated the
structure of sipunculans associated with dead coral skeletons of Diploria strigosa,
Montastraea cavernosa and Montastraea annularis-faveolata-franksi complex in Gaira
Bay (Santa Marta), from the collection of 45 samples of approximately 1 dm3. The
samples were preserved with 10% formalin and the specimens extracted manually, which
were quantified and identified to species whenever possible. All the specimens were
preserved in 70% alcohol. There were 381 individuals in approximately 37 dm3
belonging to four families, six genera and 10 species. The average density was 10.22 ±
1.25 Ind./dm3. The bioeroders Aspidosiphon cf. fischeri (48.76%) and Phascolosoma
perlucens (24.79%) were the most abundant species. While skeletons of M. cavernosa
presented the greatest abundance, greater diversity was presented in skeletons of M.
annularis-faveolata-franksi complex. The analysis of similarity (ANOSIM) showed that
there were not significant differences in the assemblage structure of sipunculans among
coral skeletons (coral species), assuming that the colonization of these organisms is rather
a product of a number of factors and conditions in the skeleton when settlement than the
skeletal structure itself. It is important to continue with studies concerning base line data
in different habitats as this would further expand our knowledge of its population
dynamics in the Colombian Caribbean.
26.1184
Icthiofauna Associated With Coral Reef System in San Esteban National Park, Venezuela
Ana HERRERA-REVELES 1,2 , José G. RODRÍGUEZ* 1
1 FACYT Universidad de Carabobo, Valencia, Venezuela, 2 PhD Ecology. I.Z.T. Universidad
Central de Venezuela, Caracas, Venezuela
The principal aim of this research was to characterize the fish community of the coral reefs of
Isla Larga and Alcatraz, located in San Esteban National Park, Venezuela. In general, 93
species from 28 families were identified within the study area using visual censuses.
Differences were observed in terms of the community structure of fishes between the two reefs;
the coral reef of Alcatraz has a greater richness of fishes, 83 species compared with 71 species
found at the Isla Larga reef. The Pomacentridae family was the most numerous at both reef
systems (47–43%, respectively). Nevertheless, differences were found between the structures of
the communities at the two different locations: the Scaridae and Acanthuridae families were
more abundant at Alcatraz, while Haemulidae was more numerous and richer in species at Isla
Larga. In spite of the fact that the herbivorous group was the most important trophic one, at all
depths in both systems, it should be emphasized that there was also a great abundance of
carnivors in Isla Larga while at Alcatraz there was greater abundance of piscivors and
corallivors. The difference in richness of species and dominant families as well as trophic group
between these systems might well due to their different types of structures: Alcatraz is a
shallow reef whose greatest depth is between 6-8 meters, while Isla Larga´s, is approximately of
18 meters. In spite of the fact that there was no evidence found of any differences in the degree
of negative impacts on the benthic communities of the two locations, it should be noted that Isla
Larga is a recreational area with a great anthropogenic activity which probably accounts for the
difference observed between the basic structures of the fish communities of the two different
systems.
Key words: Coral Reef Fishes, Fish Community Structure, Venezuela
26.1185
Biodiversity Of Cryptofauna Associated With Coral Reefs In Los Roques National Park,
Venezuela
Kira LOPEZ* 1 , David BONE 2 , Carmen RODRÍGUEZ 3 , Fabiola PADILLA 1 , Kira LOPEZ 1
1 Universidad Simón Bolívar, Caracas, Venezuela, 2 Biología de Organismos, Universidad Simón
Bolívar, Caracas, Venezuela, 3 Biología, Universidad de Carabobo, Valencia, Venezuela
The general aim of the project was to assess the biodiversity of cryptofauna associated with
coral reefs. To achieve this, the reef community was characterized in terms of its structure,
composition, abundance of organisms, and wealth of species present, paying special attention to
polychaeta. Likewise, the presence of spatial variations in the distribution of these organisms
among several locations and depths was determined. Samples were collected from colonies of
dead coral of Montastraea annularis at two different depths, 6-8 metres, and between 9-14
metres, taking three fragments in each stratum at each location. The weight, size, and volume of
the colonies were estimated for their standardization. The organisms were separated, quantified,
and identified in large groups, polychaeta families, and species in the case of Eunicidae. In all,
1463 individual specimens were found, distributed in eight taxonomic groups of which the most
abundant were sipunculids (53.73%) and polychaeta (20.98%), followed by crustaceans,
nematoda, molluscs, and equinoderms. Among the most abundant families of polychaeta were
the Eunicidae (65.9%), Syllidae (11.15%), Crysopetallidae (7.96%), and Nereididae (6.05%).
The dominant species within the Eunicidae family were Lysidice ninetta (78.7%), Marphysa cf
conferta (10.6%), and Eunice vitatta (4.8%). Qualitative analysis of some morphometric
characteristics of these coral fragments and the ANOVA (between locations and depths)
indicate no significant differences that might explain the community’s distribution in the reefs,
therefore the three locations are homogeneous and the parameters measured do not condition
the community’s structure and composition.
Key words: cryptofauna, Montastraea annularis, dead colonies, polychaeta, Eunicidae
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