scholarly journals Feeding ecology of pipefish species inhabiting Mediterranean seagrasses

Author(s):  
JULIA CASTRO-FERNÁNDEZ ◽  
INÉS CASTEJÓN-SILVO ◽  
PABLO ARECHAVALA-LOPEZ ◽  
JORGE TERRADOS ◽  
BEATRIZ MORALES-NIN

Pipefish are a vulnerable and diverse group of ichthyofauna tightly associated to seagrass meadows, key habitats in shallow marine areas. Despite of their charismatic role, main ecological features, habitat and diet of this group remain largely unknown. This study focuses on assessing pipefish habitat and feeding preferences including different hosting seagrasses such as Posidonia oceanica and Cymodocea nodosa from the Balearic Islands, western Mediterranean. Four species (Syngnathus typhle, S. abaster, Nerophis ophidion and N. maculatus) were found associated to different seagrasses. S. typhle and N. maculatus were more frequent in P. oceanica meadows, while S. abaster and N. ophidion in C. nodosa. Individuals of all species captured in P. oceanica were larger than those living in C. nodosa, suggesting a size-dependent habitat preference. Feeding preferences, however, were driven by prey availability and fish features, e.g head/snout morphology. For the first time in the western Mediterranean, a thorough description of the diet and potential preys of this group was carried out. Epifaunal assemblages (potential prey) were dominated in both habitats by harpacticoid copepods and gammarid amphipods, and they were also the primary preys according to stomach contents of all species. These results can contribute to future pipefish conservation and management actions, such as targeting crucial habitat identification and designing culture and reintroduction protocols.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Arianna Pansini ◽  
Gabriella La Manna ◽  
Federico Pinna ◽  
Patrizia Stipcich ◽  
Giulia Ceccherelli

AbstractComparing populations across temperature gradients can inform how global warming will impact the structure and function of ecosystems. Shoot density, morphometry and productivity of the seagrass Posidonia oceanica to temperature variation was quantified at eight locations in Sardinia (western Mediterranean Sea) along a natural sea surface temperature (SST) gradient. The locations are spanned for a narrow range of latitude (1.5°), allowing the minimization of the effect of eventual photoperiod variability. Mean SST predicted P. oceanica meadow structure, with increased temperature correlated with higher shoot density, but lower leaf and rhizome width, and rhizome biomass. Chlorophyll a (Chl-a) strongly impacted seagrass traits independent of SST. Disentangling the effects of SST and Chl-a on seagrass meadow shoot density revealed that they work independently, but in the same direction with potential synergism. Space-for-time substitution predicts that global warming will trigger denser seagrass meadows with slender shoots, fewer leaves, and strongly impact seagrass ecosystem. Future investigations should evaluate if global warming will erode the ecosystem services provided by seagrass meadows.


2019 ◽  
Vol 83 (4) ◽  
pp. 349
Author(s):  
Inés Castejón-Silvo ◽  
Damià Jaume ◽  
Jorge Terrados

The functional importance of herbivory in seagrass beds is highly variable among systems. In Mediterranean seagrass meadows, macroherbivores, such as the fish Sarpa salpa and the sea urchin Paracentrotus lividus, have received most research attention, so published evidence highlights their importance in seagrass consumption. The role of small crustaceans in seagrass consumption remains less studied in the region. Herbivory on Posidonia oceanica seeds has not previously been reported. In turn, crustacean herbivory on P. oceanica leaves is broadly recognized, although the species feeding on the seagrass are mostly unknown (except for Idotea baltica). This work evaluates P. oceanica consumption by two species of amphipod crustaceans commonly found in seagrass meadows. Ampithoe ramondi and Gammarella fucicola actively feed on P. oceanica leaves and seeds. Both species preferred seeds to leaves only when the seed coat was damaged. This study provides the first direct evidence of consumption of P. oceanica seeds by the two named amphipod crustaceans, and confirms that they also consume leaves of this seagrass species.


Life ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 871
Author(s):  
Antonello Mulas ◽  
Andrea Bellodi ◽  
Pierluigi Carbonara ◽  
Alessandro Cau ◽  
Martina Francesca Marongiu ◽  
...  

Cartilaginous fish are commonly recognized as key species in marine ecosystems for their fundamental ecological role as top predators. Nevertheless, effective management plans for cartilaginous fish are still missing, due to the lack of knowledge on their abundance, distribution or even life-history. In this regard, this paper aims at providing new information on the life-history traits, such as age, maturity, reproductive period, in addition to diet characteristics of eleven rare cartilaginous fish inhabiting the Central-Western Mediterranean Sea belonging to the orders Chimaeriformes (Chimaera monstrosa), Hexanchiformes (Heptranchias perlo and Hexanchus griseus), Myliobatiformes (Aetomylaeus bovinus and Myliobatis aquila), Rajiformes (Dipturus nidarosiensis and Leucoraja circularis), Squaliformes (Centrophorus uyato, Dalatias licha and Oxynotus centrina) and Torpediniformes (Tetronarce nobiliana), useful for their assessment and for future management actions. Particularly, the present paper provides for the first time the age estimation of D. nidarosienis and L. circularis which were both found capable of becoming older than ten years. In addition, the present study updates the sizes of first maturity of C. uyato and D. licha, which appeared to be capable of reproducing earlier than what was previously hypothesized, representing very valuable information for a better understanding of these rare species populations status and, eventually, their conservation. On the basis of the stomach content analysis, it was possible to identify five different predator groups.


Author(s):  
Maite Vázquez-Luis ◽  
Gàlia Banach-Esteve ◽  
Elvira Álvarez ◽  
Salud Deudero

Introduction of species is a major driver of global change and loss of biodiversity in ecosystems. The Mediterranean Sea is the most heavily invaded region in the world by introduced seaweeds. The fan mussel Pinna nobilis is the largest Mediterranean bivalve, and a protected species, present at depths from 0.5 m to 60 m. In Cabrera National Park marine protected area (MPA) (Balearic Islands, north-western Mediterranean) the population of P. nobilis is affected by the invasive seaweeds Lophocladia lallemandii and Caulerpa racemosa; however the extent of this colonization on the bivalve is unknown. Therefore, the main aims of the present study were to: (1) determine the extent of invasion of L. lallemandii and C. racemosa on the P. nobilis population; and (2) test if this invasion showed differences with depth. This is the first study assessing invasion by seaweeds on a large bivalve in a high density P. nobilis population. Pinna nobilis was distributed in all seagrass meadows surveyed within the MPA; we found a total of 872 live P. nobilis individuals, 449 and 423 of which were found at 10 and 20 m depth, respectively. High cover of L. lallemandii and low presence of C. racemosa were detected in the P. nobilis population, being quantified in 49.37% and 1.38% of the population of P. nobilis, respectively. Bathymetric differences on Lophocladia epizoism over P. nobilis has been recorded in this study; with increasing values of L. lallemandii cover index, biomass and volume at deeper depths. Pinna nobilis could be a preferential substratum for L. lallemandii in Posidonia oceanica meadows in deeper waters, acting as a stepping-stone for invasive seaweeds and facilitating the invasion throughout seagrass meadows.


2021 ◽  
Author(s):  
Arianna Pansini ◽  
Gabriella La Manna ◽  
Federico Pinna ◽  
Patrizia Stipcich ◽  
Giulia Ceccherelli

Abstract Comparing populations across temperature gradients can inform how global warming will impact the structure and function of ecosystems. Shoot density, morphometry and productivity of the seagrass Posidonia oceanica to temperature variation was quantified at eight locations in Sardinia (western Mediterranean Sea) along a natural sea surface temperature (SST) gradient. The locations are spanned for a narrow range of latitude (1.5°), allowing the minimization of the effect of eventual photoperiod variability. Mean SST predicted P. oceanica meadow structure, with increased temperature correlated with higher shoot density, but lower leaf and rhizome width, and rhizome biomass. Chlorophyll a (Chl-a) strongly impacted seagrass traits independent of SST. Disentangling the effects of SST and Chl-a on seagrass meadow density revealed that they work independently, but in the same direction with potential synergism.Space-for-time substitution predicts that global warming will trigger denser seagrass meadows with slender shoots, fewer leaves, and strongly impact seagrass ecosystem. Future investigations should evaluate if global warming will erode the ecosystem services provided by seagrass meadows.


2018 ◽  
Vol 39 (2) ◽  
pp. 145-161 ◽  
Author(s):  
Inês Freitas ◽  
Soumia Fahd ◽  
Guillermo Velo-Antón ◽  
Fernando Martínez-Freiría

Abstract The Maghreb region (North Africa) constitutes a major component of the Mediterranean Basin biodiversity hotspot. During the last centuries, a consistent human population growth has led to an unprecedented rate of habitat transformation and loss in the region and thus, threatening its biodiversity. The Western Mediterranean viper Vipera latastei-monticola inhabits humid and subhumid areas in the main mountain ranges of the Maghreb, facing such threatening factors; however, its elusive character and rarity hindered data collection for distinct biological purposes. Here, we study the biogeographical patterns and conservation status of the Maghrebian V. latastei-monticola resulting from recent sampling campaigns in Morocco and Tunisia. We update species distribution, and integrate phylogeographic and ecological niche modelling analyses at both species and lineage level to identify suitable areas, and to evaluate the impact of anthropogenic transformation and level of protection of their suitable space. We identified four highly divergent mitochondrial lineages, including a new lineage endemic to the Western High Atlas, with allopatric distributions and restricted to mountain ranges, supporting the role of mountains as past climatic refugia. Despite the remoteness of suitable areas, we report widespread habitat degradation and identify the low effectiveness of the current protected areas system in preserving the species and lineages range. Our study shows the urgent need to apply management actions for the long-term conservation of this vulnerable species and suggests a revaluation of the specific status of V. monticola, as these populations likely represent an ecotype of V. latastei.


2020 ◽  
Vol 8 (11) ◽  
pp. 911
Author(s):  
Francesca Iuculano ◽  
Carlos M. Duarte ◽  
Jaime Otero ◽  
Xosé Antón Álvarez-Salgado ◽  
Susana Agustí

Posidonia oceanica is a well-recognized source of dissolved organic matter (DOM) derived from exudation and leaching of seagrass leaves, but little is known about its impact on the chromophoric fraction of DOM (CDOM). In this study, we monitored for two years the optical properties of CDOM in two contrasting sites in the Mallorca Coast (Balearic Islands). One site was a rocky shore free of seagrass meadows, and the second site was characterized by the accumulation of non-living seagrass material in the form of banquettes. On average, the integrated color over the 250–600 nm range was almost 6-fold higher in the beach compared with the rocky shore. Furthermore, the shapes of the CDOM spectra in the two sites were also different. A short incubation experiment suggested that the spectral differences were due to leaching from P. oceanica leaf decomposition. Furthermore, occasionally the spectra of P. oceanica was distorted by a marked absorption increase at wavelength < 265 nm, presumably related to the release of hydrogen sulfide (HS−) associated with the anaerobic decomposition of seagrass leaves within the banquettes. Our results provide the first evidence that P. oceanica is a source of CDOM to the surrounding waters.


Author(s):  
Mourad Guettaf ◽  
Gustavo A. San Martin ◽  
Patrice Francour

The spawning of Paracentrotus lividus has been determined on the basis of the annual gonad index cycle at three sites in the Algiers area presenting low, intermediate and strong hydrodynamism. Three biotopes (Posidonia oceanica beds, rocky substrate with photophilous algae and overgrazed rocky substrate) and two depths (1–3 m and 6–10 m) were considered at these sites, the sex-ratio was always strongly in favour of females (2:1 to 3:1). In all sites but one, there were marked differences in the gonad index and the spawning period between sites; the gonad index reached its maximum value at the site with the weakest hydrodynamism, and the minimum value at the site with the strongest hydrodynamism. Spawning took place in April–May and August–September at the site with the weakest hydrodynamism, in April–June and October–December at the site with intermediate hydrodynamism and only in winter at the site with maximum hydrodynamism. The coexistence, on regional scale, of these reproductive cycles might enable Paracentrotus lividus to compensate the mortality during planktonic larval phase by the fact that spawning of this sea urchin occurred in all seasons.


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