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Vermaak A, Kudlai O, Yong RQY, Smit NJ. Novel insights into the genetics, morphology, distribution and hosts of the global fish parasitic digenean Proctoeces maculatus (Looss, 1901) (Digenea: Fellodistomidae). Parasitology 2023; 150:1242-1253. [PMID: 37905529 PMCID: PMC10801382 DOI: 10.1017/s0031182023001026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/22/2023] [Accepted: 10/20/2023] [Indexed: 11/02/2023]
Abstract
Larval stages of the widely distributed digenean species Proctoeces maculatus (Looss, 1901) were reported 40 years ago from South Africa in the common octopus, Octopus vulgaris Cuvier (Octopodidae). However, the absence of adult specimens and molecular data from this region has hindered a comprehensive understanding of its distribution. In this study, we collected three species of intertidal and near-shore marine fishes [Clinus superciliosus (L.) (Clinidae), Diplodus capensis (Smith) (Sparidae) and Sparodon durbanensis (Castelnau) (Sparidae)] along the South African coast and discovered adult specimens of P. maculatus at five localities. By employing a combination of morphological and molecular techniques, including 28S rDNA, 18S rDNA and COI mtDNA analyses, the first report of adult P. maculatus from South Africa is presented. The findings encompass a comprehensive morphological description and molecular data, illuminating the true distribution of this species in the region.
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Affiliation(s)
- Anja Vermaak
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, 2520 Potchefstroom, South Africa
| | - Olena Kudlai
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, 2520 Potchefstroom, South Africa
- Institute of Ecology, Nature Research Centre, 08412 Vilnius, Lithuania
| | - Russell Q-Y. Yong
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, 2520 Potchefstroom, South Africa
| | - Nico J. Smit
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, 2520 Potchefstroom, South Africa
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Khan U, Bal H, Battal ZS, Seyhan K. Using otolith and body shape to discriminate between stocks of European anchovy (Engraulidae: Engraulis encrasicolus) from the Aegean, Marmara and Black Seas. JOURNAL OF FISH BIOLOGY 2022; 101:1452-1465. [PMID: 36097416 DOI: 10.1111/jfb.15216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 09/08/2022] [Indexed: 06/15/2023]
Abstract
European anchovy, a small pelagic fish, plays a significant role in the blue economy, with remarkable commercial, ecological and culinary values. In this study, the variability in the shapes of the body and sagitta otoliths was examined to identify the different anchovy stocks in the Black Sea (26.5°E-39.9°E, 38.7° N-42.1°N) and adjacent regions, i.e., the Sea of Marmara and the Aegean Sea. The body shape was assessed with geometric morphometrics, while shape indices and elliptic Fourier analysis were used to evaluate the shape of the sagitta otoliths. The data were analysed using multivariate and univariate analysis of variance, discriminant function and principal component analysis. The anchovy population could be divided into five distinct stocks based on body shape, with an overall leave-one-out cross-validated correct classification of 85.6%. The geometric morphometrics revealed significant differences in body depth, snout, lower jaw and caudal fin. The differences in sagitta otolith shape also revealed the existence of four distinct stocks with an overall leave-one-out cross-validated correct classification of 46.5%-69.3%. The elliptic Fourier analysis revealed two main stocks of anchovy from the Black Sea as the Eastern-Middle Black Sea stock and the Western Black Sea stock. Based on the elliptic Fourier analysis, the differences in the sagitta otoliths increase in magnitude with increasing geographic separation, first manifested at the otolith anterior notch, followed by changes in the otolith width. The findings affirmed the existence of distinct stocks that should have important implications for effective management of this pelagic fish in the Black Sea and adjacent regions.
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Affiliation(s)
- Umar Khan
- Institute of Marine Sciences and Technology, Karadeniz Technical University, Trabzon, Türkiye
| | - Habib Bal
- Republic of Türkiye Ministry of Agriculture and Forestry, Erdek Directorate of District Agriculture and Forestry, Department of Fisheries, Erdek, Türkiye
| | | | - Kadir Seyhan
- Department of Maritime Business Administration, Faculty of Marine Science, Karadeniz Technical University, Trabzon, Türkiye
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Inferring Population Structure from Early Life Stage: The Case of the European Anchovy in the Sicilian and Maltese Shelves. WATER 2022. [DOI: 10.3390/w14091427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The European anchovy is an important fishing resource in the Sicilian Channel that supports a high recruitment success variability. The presence of two spawning areas, the drifting of the larvae along the currents and the different oceanographic conditions within the region suggest the presence of different larvae subpopulations. Morphometric and biochemical approaches have been used to analyze the differences among larvae collected. The amino acid composition discriminates two larval groups closely related to the spawning regions: Adventure Bank and the shelf between the South of Sicily and Malta. In addition, there are morphometric and growth differences between recently hatched larvae in these two regions, reinforcing the hypothesis of two larval subpopulations and suggesting differences in the parental reproduction effort. Between the South of Sicily and Malta there are growth and biochemical composition differences since larvae from the Maltese coast present a higher protein content and a bigger growth rate than those from Sicily, pointing out that Malta is an area with a better nutritional condition environment. No differences in the growth rate have been observed between the Adventure Bank area and the Maltese shelf, therefore, a diverse nutritional condition cannot be suggested between these two areas despite the Maltese larvae having a higher protein content present.
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Predicting Potential Spawning Habitat by Ensemble Species Distribution Models: The Case Study of European Anchovy (Engraulis encrasicolus) in the Strait of Sicily. WATER 2022. [DOI: 10.3390/w14091400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Species distribution models (SDMs) are important tools for exploring the complex association between species and habitats. Here, we applied six SDMs combining 1946 pieces of presence/absence data regarding European anchovy eggs with environmental parameters from surveys conducted in the Strait of Sicily from 1998 to 2016. We aimed to investigate the mechanisms influencing spawning habitat suitability for anchovy (Engraulis encrasicolus). The dataset was split into a training subset (75%) and a test subset (25%) for evaluating the predictive performance of the models. The results suggested the role of environmental parameters in explaining egg occurrence, model accuracy and spatial predictions. Bottom depth consistently had the highest importance, followed by absolute dynamic topography, which gives insights about local mesoscale oceanographic features. Each modelling method, except the linear model, produced successful performance for both the training and the test datasets. The spatial predictions were estimated as weighted averages of single-model predictions, with weights based on discriminatory power measured by the area under the receiver operating characteristic curve (AUC). This ensemble approach often provided more robust predictions than a single model. The coastal waters were identified as the most favorable for anchovy spawning, especially the south-central sector and the area around the southern-most tip of Sicily.
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Gregorietti M, Atzori F, Carosso L, Frau F, Pellegrino G, Sarà G, Arcangeli A. Cetacean presence and distribution in the central Mediterranean Sea and potential risks deriving from plastic pollution. MARINE POLLUTION BULLETIN 2021; 173:112943. [PMID: 34562663 DOI: 10.1016/j.marpolbul.2021.112943] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 09/03/2021] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
The Sardinian and Sicilian Channels are considered hotspots of biodiversity and key ecological passages between Mediterranean sub-basins, but with significant knowledge gaps about marine mammal presence and potential threats they face. Using data collected between 2013 and 2019 along fixed transects, inter and intra-annual cetacean index of abundance was assessed. Habitat suitability, seasonal hot spots, and risk exposure for plastic were performed using the Kernel analysis and the Biomod2 R-package. 661 sightings of 8 cetacean species were recorded, with bottlenose and striped dolphins as the most sighted species. The north-eastern pelagic sector, the coastal waters and areas near ridges resulted the most suitable habitats for these species. The risk analysis identified the Tunis, Palermo, and Castellammare gulfs and the Egadi Island as areas of particular risk of plastic exposure. The study represents a great improvement for cetacean knowledge in this region and contributes to the development of effective conservation strategies.
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Affiliation(s)
- M Gregorietti
- Laboratorio di Ecologia, Dipartimento di Scienze della Terra e del Mare, Viale delle Scienze Ed. 16, 90128 Palermo, Italy; Accademia del Leviatano, Via dell'Ospedaletto 53/55, Roma, Italy.
| | - F Atzori
- Area Marina Protetta Capo Carbonara, via Roma 60, Villasimius, Italy
| | - L Carosso
- Area Marina Protetta Capo Carbonara, via Roma 60, Villasimius, Italy
| | - F Frau
- Area Marina Protetta Capo Carbonara, via Roma 60, Villasimius, Italy
| | - G Pellegrino
- Accademia del Leviatano, Via dell'Ospedaletto 53/55, Roma, Italy
| | - G Sarà
- Laboratorio di Ecologia, Dipartimento di Scienze della Terra e del Mare, Viale delle Scienze Ed. 16, 90128 Palermo, Italy
| | - A Arcangeli
- ISPRA Bio Dep., via Brancati 60, 00144 Roma, Italy
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Dall'Olmo G, Nencioli F, Jackson T, Brewin RJW, Gittings JA, Raitsos DE. Ocean Lagrangian Trajectories (OLTraj): Lagrangian analysis for non-expert users. OPEN RESEARCH EUROPE 2021; 1:117. [PMID: 37645140 PMCID: PMC10445858 DOI: 10.12688/openreseurope.14133.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/04/2021] [Indexed: 08/31/2023]
Abstract
Lagrangian analysis is becoming increasingly important to better understand the ocean's biological and biogeochemical cycles. Yet, biologists and chemists often lack the technical skills required to set up such analyses. Here, we present a new product of pre-computed ocean Lagrangian trajectories (OLTraj) targeting non-expert users, and demonstrate how to use it by means of worked examples. OLTraj is based on satellite-derived geostrophic currents, which allows one to directly compare it with other in-situ or satellite products. We anticipate that OLTraj will foster a new interest in Lagrangian applications in ocean biology and biogeochemistry.
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Affiliation(s)
- Giorgio Dall'Olmo
- Plymouth Marine Laboratory, Plymouth, England, PL1 3DH, UK
- National Centre for Earth Observation, Plymouth, England, PL1 3DH, UK
| | - Francesco Nencioli
- Collecte Localisation Satellites (CLS), Ramonville Saint-Agne, 31520, France
| | - Thomas Jackson
- Plymouth Marine Laboratory, Plymouth, England, PL1 3DH, UK
| | - Robert J. W. Brewin
- Centre for Geography and Environmental Science, College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall, UK
| | - John A. Gittings
- Department of Biology, National and Kapodistrian University of Athens, Athens, 157 72, Greece
| | - Dionysios E. Raitsos
- Department of Biology, National and Kapodistrian University of Athens, Athens, 157 72, Greece
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