11th ICRS Abstract book - Nova Southeastern University

Poster Mini-Symposium 26: Biodiversity and Diversification of Reef Organisms
26.1194
Morphological And Genetic Variation Implicates Monotypy For briareum
(Anthozoa: Octocorallia) in The Western Atlantic
Jaret BILEWITCH* 1 , Kathryn COATES 2
1 Dept. of Geology, University at Buffalo, Buffalo, NY, 2 Dept. of Conservation Services,
Bermuda Ministry of the Environment, Flatts, Bermuda
Subjective disagreement exists regarding the taxonomic status of two growth forms of the
octocoral Briareum Blainville 1830 in the Western Atlantic; some studies refer to
encrusting colonies as a separate species, B. polyanthes Duchassaing & Michelotti 1860,
while others equate it with a digitate form B. asbestinum (Pallas 1766). We quantified the
degree of both genetic and morphological variation within and between growth forms in
an attempt to clarify their taxonomic status. Morphological variation was quantified by
measuring sclerite lengths and comparing mean values between colony growth forms and
geographic locations of Briareum samples collected from Bermuda and the Bahamas.
Genetic variation was examined with sequences of msh mtDNA and cloned ITS1-5.8S-
ITS2 rDNA. Both morphological and molecular results support a single-species status of
Briareum in the Western Atlantic. More significant morphological variation was seen
within each growth form than between them. Within the encrusting form, significant
differences existed between mean sclerite lengths of colonies from Bermuda versus the
Bahamas. DNA evidence was unable to differentiate growth forms. While msh mtDNA
sequences were invariable across all colonies, the sequences of cloned rDNA indicated
high levels of intra-genomic variation. However, the most commonly recovered rDNA
haplotypes were shared between growth forms, suggesting little or no divergence. We
interpret the sharing of many rDNA haplotypes between growth forms as evidence of
either ongoing interbreeding or incipient divergence with incomplete lineage sorting.
Given our observations that geographical variation within a growth form exceeds
variation between growth forms and that a highly variable molecular marker is incapable
of distinguishing between growth forms, there is currently no evidence for treating each
as a separate species and we recommend adhering to the last valid taxonomic treatment,
which synonymizes both under Briareum asbestinum.
26.1195
Patterns Of Zooxanthellate Scleractinia Biodiversity In New Caledonia
Francesca BENZONI* 1 , Gregory LASNE 2 , Michel PICHON 3 , Claude PAYRI 2
1 Dept. of Biotechnologies and Biosciences, University of Milan-Bicocca, Milano, Italy,
2 Institut de Recherche pour le Développement (IRD) Noumea, Noumea, New Caledonia,
3 Ecole Pratique des Hautes Etudes, Perpignan, France
The coral reefs around New Caledonia cover a total estimated surface of 4.538 km2. A
wide range of reef geomorphologies and environmental conditions provide a diverse
array of conditions for reef organisms. Taxonomic surveys of important reef taxa such as
algae and crustaceans have been conducted. However, a limited number of studies have
addressed the total biodiversity of reef Scleractinia and species distribution in New
Caledonia. Moreover, the coral fauna of some neocaledonian coral reefs has never been
studied until recently. In 2007 two scientific cruises organised by the Institut de
Recherche pour le Développement (IRD) of Noumea have allowed for the first time the
scientific exploration of two previously poorly known reef areas in the Southern
Province: the Cote Oubliée, on the east side of the main island, and the Cap Bourail
region, on the west side, respectively. During both expeditions a taxonomic survey of
zooxanthellate Scleractinia has been conducted on coral reefs with different
geomorphologic features and exposed to different environmental conditions. The main
results of these taxonomic surveys are the first assessment of the extent of coral
biodiversity in the examined reefs in the Cote Oubliée and Cap Bourail and the survey of
coral species distribution showing some strong patterns between different reef types in
both regions.
26.1196
Cryptic Diversity Of Sea Cucumbers: The Nocturnal Monsters, bohadschia
(Holothuroidea: Holothuriidae)
Sun KIM* 1 , Alexander KERR 2 , Gustav PAULAY 3
1 Marine Laboratory, University of Guam, Mangilao, 2 Marine Laboratory, University of Guam,
Mangilao, Guam, 3 Florida Museum of Natural History, University of Florida, Gainesville, FL
Sea cucumbers are among the most poorly studied macrobiota on coral reefs. For example, the
genus Bohadschia (Holothuroidea: Holothuriidae) is often considered one of the most
taxonomically controversial groups. In this study, we investigated the systematics of this group
using field and molecular methods. Initial findings include that the morphologically and
ecologically distinct B. argus is derived within the taxonomically muddled marmoratacomplex.
Also, a clade, B. bivittata in part, has tiny lines over its dorsum, a character that was
not previously considered taxonomically important. In addition, several species, including B.
koellikeri appear to be hybrids. Finally, we have a lot more to learn about their systematics on
reefs worldwide, as we are discovering many new Bohadschia species.
26.1197
The Abundance, Size Classes And Diversity Of Fish in Various Reef Microhabitats At
Bongoyo Island
Prisca MZIRAY* 1 , Gregory M. WAGNER 2
1 Research, Tanzania Fisheries Research Institute, Kigoma, Tanzania, 2 Faculty of Aquatic
Sciences and Technology, University of Dar es Salaam, Dar es Salaam, Tanzania
The purpose of this study was to compare the abundance, size classes and species diversity of
fish in different microhabitats associated with the coral reef on the sheltered, northwest side of
Bongoyo Island in Dar es Salaam Marine Reserve System (DMRS). Data were collected from
five different microhabitats (i.e., mixed hard coral, Acropora, Galaxea, seagrass and rubble) by
repeated observations (3-min intervals) using a simple visual method whereby fish were
recorded by species and size categories.
Results showed that, there was an extremely significant difference in total fish counts, with all
species and size categories combined, among the five microhabitats (randomized block
ANOVA: F = 20.655 DF1 = 4, DF2 = 44, p < O 0001), with Acropora having the highest
counts, probably since the branches provide protection, especially for small fish species and
juveniles. Fish biomass index of all species combined also showed an extremely significant
difference amongst microhabitats (F = 20.655, DF1 = 4, DF2 = 44, p < 0.0001), again with
Acropora having the highest values. Species diversity (Shannon-Weaver Index) was highest in
mixed hard coral, probably due to the variety of hard coral structures which create numerous
microhabitats. In this study, almost all fish were of the small size category (0 – 10 cm),
indicating serious overfishing in the area.
It is recommended that appropriate management and conservation actions be implemented to
eliminate coral reef destruction and overfishing. There should be regular monitoring on the
reefs for early detection of any significant negative changes.
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