Patterns of variation in behaviour within and among reef fish species on an isolated tropical island: influence of exposure and substratum

2010 ◽  
Vol 91 (6) ◽  
pp. 1359-1368 ◽  
Author(s):  
João Paulo Krajewski ◽  
Sergio R. Floeter ◽  
Geoffrey P. Jones ◽  
Fosca P.P. Leite
Keyword(s):  
Reef Fish ◽  
Water Flux ◽  
Trophic Group ◽  
Wave Exposure ◽  
Activity Budgets ◽  
North East ◽  
Rocky Reefs ◽  
Fernando De Noronha ◽  
Save Energy ◽  
Species Specific

Here we studied the activity budgets of nine common reef fish in the oceanic archipelago of Fernando de Noronha, off north-east Brazil. Species were variable in their behaviour between different sites and similarities in their activity budgets were not necessarily associated with their trophic group. For four species we investigated the relationship of their activity budgets to wave exposure and substratum composition. Staying close to the substratum was positively correlated to wave exposure for most species and foraging was negatively correlated to exposure for two species. By behaving this way, these fish may save energy by avoiding swimming in higher water flux. In contrast to relationships with wave exposure, the responses to substratum composition were species specific. Our results highlight that the activity budgets of fish living in oceanic rocky reefs can be variable and influenced by the local and temporal variation in environmental variables.

Spatiotemporal variation in the structure of reef fish and macroalgal assemblages in a north-east Atlantic kelp forest ecosystem: implications for the management of temperate rocky reefs

2018 ◽  
Vol 69 (4) ◽  
pp. 525 ◽  
Author(s):  
Pablo Pita ◽  
Diana Fernández-Márquez ◽  
Juan Freire
Keyword(s):  
Reef Fish ◽  
Fish Assemblages ◽  
Kelp Forest ◽  
Habitat Destruction ◽  
Kelp Forests ◽  
Rocky Reef ◽  
Laminaria Hyperborea ◽  
East Atlantic ◽  
North East ◽  
Rocky Reefs

Temperate rocky reefs and kelp forest ecosystems have been severely affected by overfishing, pollution and habitat destruction, and climate change is a major driver of kelp decline in many regions. Although necessary for management, ecological interactions between kelp and fish remain largely unknown in the north-east Atlantic. In the present study, underwater visual censuses (UVC) and univariate and multivariate multiple regression models were used to analyse the spatiotemporal variations in the abundance and habitat use of the rocky reef fish and macroalgae assemblages of Galicia (north-west Spain). The underwater seascape was dominated by large rocks and kelp forests of Laminaria hyperborea, L. ochroleuca and Saccorhiza polyschides. Fish assemblages were ruled by gadids, labrids and sparids. The most frequent fish species were Labrus bergylta (counted in 90% of UVC) and Pollachius pollachius (in 100% of UVC), whereas the most abundant were Boops boops (mean±s.d., 556.4±39.7 individuals ha–1) and L. bergylta (432.10±440.05 individuals ha–1). Fish and macroalgal assemblages showed different spatial preferences and responded strongly to seasonality, wave exposure and depth. To a lesser degree, fish and macroalgal assemblages showed preferences for habitat structure. Moreover, because the findings of the present study indicate that L. bergylta is a good indicator species of the health of rocky reef and kelp forests ecosystems, monitoring of this fish can be helpful for management and conservation actions.

Shipwrecks fouling community: Similarities with natural rocky reefs at different distances and wave exposure regimes

2021 ◽  
Vol 213 ◽  
pp. 105895
Author(s):  
Taciana Kramer Pinto ◽  
Felipe P.A. Barros ◽  
José Anchieta C.C. Nunes ◽  
Ricardo J. Miranda ◽  
Bruno M.S. Pereira ◽  
...  
Keyword(s):  
Wave Exposure ◽  
Fouling Community ◽  
Rocky Reefs

Responses of fine root exudation, respiration, and morphology in three early successional tree species to increased air humidity and different soil nitrogen sources

2021 ◽  
Author(s):  
Marili Sell ◽  
Ivika Ostonen ◽  
Gristin Rohula-Okunev ◽  
Linda Rusalepp ◽  
Azadeh Rezapour ◽  
...  
Keyword(s):  
Soil Nitrogen ◽  
Root Morphology ◽  
Fine Roots ◽  
Root Respiration ◽  
Fine Root ◽  
Water Flux ◽  
Nitrogen Sources ◽  
Air Humidity ◽  
Fine Root Morphology ◽  
Species Specific

Abstract Global climate change scenarios predict an increase in air temperature, precipitation, and air humidity for northern latitudes. Elevated air humidity may significantly reduce the water flux through forest canopies and affect interactions between water and nutrient uptake. However, we have limited understanding of how altered transpiration would affect root respiration and carbon (C) exudation as fine root morphology acclimates to different water flux. We investigated the effects of elevated air relative humidity (eRH) and different inorganic nitrogen sources (NO3− and NH4+) on above and belowground traits in hybrid aspen (Populus × wettsteinii Hämet-Ahti), silver birch (Betula pendula Roth.), and Scots pine (Pinus sylvestris L.) grown under controlled climate chamber conditions. The eRH significantly decreased the transpiration flux in all species, decreased root mass-specific exudation in pine, and increased root respiration in aspen. eRH also affected fine root morphology, with specific root area increasing for birch but decreasing in pine. The species comparison revealed that pine had the highest C exudation, while birch had the highest root respiration rate. Both humidity and nitrogen treatments affected the share of absorptive and pioneer roots within fine roots; however, the response was species-specific. The proportion of absorptive roots was highest in birch and aspen, the share of pioneer roots was greatest in aspen, and the share of transport roots was greatest in pine. Fine roots with lower root tissue density were associated with pioneer root tips and had a higher C exudation rate. Our findings underline the importance of considering species-specific differences in relation to air humidity and soil nitrogen availability that interactively affect the C input–output balance. We highlight the role of changes in the fine root functional distribution as an important acclimation mechanism of trees in response to environmental change.

scholarly journals Turtle cleaners: reef fishes foraging on epibionts of sea turtles in the tropical Southwestern Atlantic, with a summary of this association type

2010 ◽  
Vol 8 (1) ◽  
pp. 187-192 ◽  
Author(s):  
Cristina Sazima ◽  
Alice Grossman ◽  
Ivan Sazima
Keyword(s):  
Reef Fish ◽  
Fish Species ◽  
Sea Turtles ◽  
Reef Fishes ◽  
Oceanic Islands ◽  
Southwestern Atlantic ◽  
Cleaning Symbiosis ◽  
Turtle Species ◽  
Fernando De Noronha ◽  
Reef Fish Species

In the present study we record several instances of reef fish species foraging on epibionts of sea turtles (cleaning symbiosis) at the oceanic islands of Fernando de Noronha Archipelago and near a shipwreck, both off the coast of Pernambuco State, northeast Brazil. Nine reef fish species and three turtle species involved in cleaning are herein recorded. Besides our records, a summary of the literature on this association type is presented. Postures adopted by turtles during the interaction are related to the habits of associated fishes. Feeding associations between fishes and turtles seem a localized, albeit common, phenomenon.

A new species of Gastrophanella from central western Atlantic, with a discussion of the family Siphonidiidae (Demospongiae: Lithistida)

2000 ◽  
Vol 80 (4) ◽  
pp. 599-605 ◽  
Author(s):  
G. Muricy ◽  
J.V. Minervino
Keyword(s):  
New Species ◽  
New Caledonia ◽  
Valid Species ◽  
Brazilian Coast ◽  
Western Atlantic ◽  
North East ◽  
The Family ◽  
Fernando De Noronha ◽  
The Caribbean ◽  
A New Species

A new species of Gastrophanella, G. cavernicola sp. nov. (Demospongiae: Siphonidiidae), is described from submarine caves in Fernando de Noronha Island (north-east Brazil), Carrie Bow Cay and Columbus Cay, Belize (central Western Atlantic), at depths of 5-30 m. It differs from all other species of the genus by its lobate shape with thin superficial canals and centrotylote tylostrongyles. Gastrophanella cavernicola sp. nov. is the second record of the genus Gastrophanella from both Brazil and the Caribbean. It is the sixth ‘lithistid’ sponge reported from the Brazilian coast, whereas at least 32 other desma-bearing sponges are known from the Caribbean. The genus now includes five valid species, G. implexa Schmidt from the West Indies (type species), G. mammilliformis Burton from South Africa, G. primore Gómez from the Pacific Coast of Mexico, G. stylifera Mothes & Silva from south Brazil, and G. cavernicola sp. nov. from north-east Brazil and Belize. Aciculites oxytylota Lévi & Lévi from New Caledonia is transferred to Siphonidium Schmidt. The family Siphonidiidae Lendenfeld, which is probably related to order Hadromerida, is redefined to contain only Siphonidium and Gastrophanella, both with fused rhizoclone desmas associated to microspined exotyles.

Morphological and molecular analyses of larval taeniid species in small mammals from contrasting habitats in Denmark

2013 ◽  
Vol 89 (1) ◽  
pp. 112-117 ◽  
Author(s):  
M.N.S. Al-Sabi ◽  
P.M. Jensen ◽  
M.U. Christensen ◽  
C.M.O. Kapel
Keyword(s):  
Multiplex Pcr ◽  
Small Mammals ◽  
Habitat Type ◽  
Prevalence Rates ◽  
Intermediate Hosts ◽  
Morphological Examination ◽  
Species Determination ◽  
North East ◽  
Significant Difference ◽  
Species Specific

AbstractTaeniid infections in intermediate hosts manifest themselves as extraintestinal larval stages which, in early development, lack species-specific characteristics. The inability to distinguish infections of zoonotic importance such as Echinococcus multilocularis from other taeniid infections that have mainly veterinary significance stimulated the development of species-specific molecular diagnostics. In this study, the prevalence of taeniid infections in potential intermediate hosts was evaluated using both morphological diagnosis and a newly described multiplex polymerase chain reaction (PCR) for species determination. Small mammals (N= 719) were trapped in three different types of habitats in north-east Zealand, Denmark. The sensitivity of the multiplex PCR (90.5%) exceeded that of morphological examination (57.9%) for identifying 95 taeniid infections. The use of the multiplex PCR resulted in higher prevalence rates due to improved detection of immature liver infections with Hydatigera taeniaeformis and Versteria mustelae, but did not affect the observed prevalence rates of peritoneal metacestodes of Taenia polyacantha. The prevalence of taeniid infections showed a significant difference according to habitat type, potentially identifying a ‘sylvatic’ transmission and an ‘urban’ transmission, with marked variation among different taeniid species. Versteria mustelae and T. polyacantha were more prevalent in rural forests, while infections with H. taeniaeformis were dominant in urban parks/forests and in residential and farm gardens. The multiplex PCR facilitated a better utilization of wildlife samples by yielding a higher number of definitive diagnoses of ambiguous taeniid infections in liver lesions, allowing for more accurate epidemiological data and, hence, a more accurate risk assessment.

Corrigendum to: In situ target strength measurement of the black triggerfish Melichthys niger and the ocean triggerfish Canthidermis sufflamen

2021 ◽  
Vol 72 (3) ◽  
pp. 449
Author(s):  
Julie Salvetat ◽  
Anne Lebourges-Dhaussy ◽  
Paulo Travassos ◽  
Sven Gastauer ◽  
Gildas Roudaut ◽  
...  
Keyword(s):  
Target Strength ◽  
Biomass Estimation ◽  
Tropical Islands ◽  
Acoustic Data ◽  
North East ◽  
Fernando De Noronha ◽  
The Mean ◽  
Tuna Fisheries ◽  
Fish Aggregating Devices

Triggerfish are widely distributed in tropical waters where they play an important ecological role. The black triggerfish Melichthys niger may be the dominant species around oceanic tropical islands, whereas pelagic triggerfish, such as the ocean triggerfish Canthidermis sufflamen, can assemble around fish aggregating devices (FADs) where they are a common bycatch of tuna fisheries. In this study we combined acoustic and optical recordings to provide the first in situ target strength (TS) measurement of black and ocean triggerfish. Data were collected in the Archipelago of Fernando de Noronha off north-east Brazil. The mean TS of a 27.8-cm-long black triggerfish at 70 and 200kHz was –39.3dB re 1m2 (CV=14.0%) and –38.9dB re 1m2 (CV=14.4%) respectively. The mean TS values of ocean triggerfish (with a size range of 39–44cm) at 70 and 200kHz were –36.0dB re 1m2 (CV=15.7%) and –33.3dB re 1m2 (CV=14.0%) respectively. This work opens up the field for acoustic biomass estimates. In addition, we have shown that TS values for ocean triggerfish are within the same range as those of small tunas. Therefore, acoustic data transmitted from FADs equipped with echosounders can introduce a bias in tuna acoustic biomass estimation and lead to increased rates of bycatch.

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