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In the spur-and-groove reefs of the Ecological Reserve Siboney-Juticí (Southeast Cuba) octocorals are one of the predominant components of the sessile fauna. Main objectives of the present paper are characterizing the composition, structure and conservation status of the octocoral communities and assessing on the prevailing environmental conditions in the study area. For data collection, six sampling sites were located every 2-3 km ranging from 12 m to 17 m depth along the spur-and-groove reefs. In each site, 22-26 lm2 quadrants were zigzag arranged every 2 m. The density of colonies was determined per site. The severity degree and predictability of environmental conditions were inferred by using the Heterogeneity and Equitability indexes, respectively. Hydrodynamic stress and the Comparative Pollution Index were also assessed. Current affectations of the octocoral communities were also determined and classified into four main categories: mechanical damage, diseases, predation and invertebrate and macroalgae overgrowth. As a result, 25 species represented by 752 colonies were recorded and Eunicea flexuosa and Gorgonia ventalina were the most abundant. The occurrence of Eunicea succinea forma succinea constituted the first report for Eastern Cuba. Site densities ranged from 3.58 +/- 1.84 to 7.58 +/- 2.16 colonies/m2 and considered from moderate to low. The biggest densities were reported at both sides of the San Juan River mouth. Despite of the composition and structure of the octocoral communities, low to high hydrodynamic stress and low and moderate levels of contamination were inferred, it is likely that these indexes could have been overestimated due to the sensitivity of the indicator species to other factors such as sedimentation. The environmental conditions were mostly favorable and stable. In general, the number of dead colonies was low and mostly caused by the detachment of the substrate and overgrowth of Millepora alcicornis. Injuries were mainly brought about by mechanical damage, followed by coenenchyme loss, predation by Cyphoma gibbosum and macroalgae overgrowth. On the other hand, negative effects by Hermodice carunculata predation, bleaching, Red Band and Black Band Disease were not observed. Among sampled species, G. ventalina colonies were the most severely damaged within the community. As a whole, octocoral communities of spur-and-groove reefs in the Ecological Reserve Siboney-Juticí showed a good conservation status.

On the basis of fishery intensity and proximity to river mouth, a total of 257 swimming Callinectes crabs were collected from March 2007 to April 2008 in eight localities. Captures were made with hanging nets, to a maximal depth of 1.5 m, establishing a top time of 2 hr. The genus was widely distributed, and it is represented at least by four species: C. sapidus, C. similis, C. rathbunae and C. larvatus, the last two not included in the last list of Cuban crustaceans (Crustacea: Decapoda). The size and shape of the gonopods were very useful as taxonomical criteria, considering the prevalence of males. The most abundant species were C. sapidus (47.08%), and C. similis (30.35%). C rathbunae, which was identified at 75% (6) of the localities, showed a better distribution, followed by C. sapidus, which appears in the 63% (5). Sex rate (R(s)) by species (male:female) was 6.20 for C. rathbunae, 3.58 for C. similis, 1.40 for C. larvatus and 0.40 for C. sapidus. The most abundant species had a lower R value. Morphometrical analysis and weight allowed us to know the average carapace width (CW) and weight (W). C. sapidus had an average CW = 110.57 mm (DS 21.55, n = 121) and W = 84.46 g (SD 43.25, n = 121); C. rathbunae a CW = 115.50 mm (DS 14.94, n = 36) and W = 140.44 g (DS 55.02, n = 36); C. larvatus a CW = 76.04 mm (DS 10.88, n = 22) and W = 31.70 g (DS 14.67, n = 22); and C. similis had the minimal parameter values, with a CW = 59.77 mm (DS 14.09, n = 78) and W = 13.80 g (DS 10.00, n = 78). These are the first records of the coastal crabs in the area. All values are lower than in previous reports. The largest individuals (CW>140 mm: C. rathbunae and C. sapidus) were captured in localities with adequate environmental characteristics. The stomach content suggests nine dietary categories, mainly fishes and macroalgae. The genus Callinectes has a diversified trophic spectrum. These crabs eat the available food, but they have a preference for the most abundant items.