•Genetic diversity was high for resident goatfish species in Egypt but lower for the migrant species.•No genetic partitioning for all three goatfish species based on AMOVA and network analyses.•The ...Delta Nile outflow may not pose a significant barrier to larval dispersal for goatfish.
We examined the genetic diversity and connectivity of two indigenous Mediterranean goatfish species (Mullus barbatus and M. surmuletus), and a Lessepsian migrant species (Upeneus moluccensis), across the Nile Delta outflow using two mitochondrial DNA markers (COI and cyt b). Genetic diversity was high for the two Mediterranean species but relatively lower for the migrant species, suggesting founder effects after invasion from the Red Sea. Confirmation of this hypothesis, however, would require comparison with populations of origin in the Red Sea and the broader Indo-West Pacific. AMOVA and network analyses revealed no genetic partitioning for all species, indicating that the Nile outflow does not currently, and may not have historically, posed a significant barrier to larval dispersal in these goatfish, despite a present-day temperature and salinity gradient along the Mediterranean coastline of Egypt.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We report four new species of monorchiids infecting teleost fishes from Australian waters. Two new species of Paralasiotocus Wee, Cutmore, Pérez-del-Olmo & Cribb, 2020, Pa. abstrusus n. sp. and Pa. ...tectus n. sp., are described from haemulids of the Great Barrier Reef. The two species are morphologically cryptic and occur in sympatry but differ significantly in cox1 mtDNA and ITS2 rDNA sequence data. Paralasiotocus tectus n. sp. is found only in Plectorhinchus albovittatus (Rüppell) whereas Pa. abstrusus n. sp. infects Pl. albovittatus, Plectorhinchus flavomaculatus (Cuvier) and Plectorhinchus lineatus (Linnaeus). The two species differ from all known species of Paralasiotocus in the possession of a clear gap in the spines of the terminal organ. A new species is described from a mullid, Parupeneus spilurus (Bleeker), from off Heron Island and Moreton Bay. The new species is morphologically broadly consistent with the concept of Paralasiotocus in the possession of an unspined genital atrium, bipartite terminal organ, and lobed ovary. However, it possesses a highly lobed cirrus and is phylogenetically widely separated from the two species of Paralasiotocus characterized here, and thus we propose Lobucirruatus infloresco n. g., n. sp. Proctotrema prominens n. sp., is described from Pl. albovittatus. It is differentiated from all other species of Proctotrema in the combination of a prominent metraterm, slightly fusiform body, slightly funnel-shaped oral sucker, elongate cirrus-sac, unlobed ovary, and caeca that terminate in the post-testicular region.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this study, we aimed to examine the status and historical change of trawl fishing fleet in the Foça in the Aegean Sea. The data of the study representing all actively working trawlers in 1998-1999 ...and 2019 were collected through face-to-face interviews with trawler boat owners in Foca. The questionnaire consisted of questions related to the characteristics of the vessels, fishing activity, socio-demographics of fishers, running costs, annual landings of species and management issues. The study indicated that the annual landings of the main target species significantly decreased over the last two decades. Fishers reported the landings of some species including Dentex gibbosus, Dentex macrophthalmus, Homarus gammarus, Mustelus mustelus, Octopus vulgaris, Parapenaus longirostris, Scomber colias, Scorpaena porcus, Scorpaena scrofa, Spicara smaris, Trachurus spp. and Zeus faber decreased considerably over this period. Over the same period, a decrease was found in the mean length of Merluccius merluccius, Lophius piscatorius and Zeus faber. The vessels’ fuel tank volume and tow duration showed significant increases from 1999 to 2019. The trawl fleet decreased by ~75% from 1999 to 2019 and 55% of the current fishers reported that they may leave the fishery sector within the next 10 years. A change was also determined in the tradition of the sharing system, which is the number of crews paid in shares rather than a fixed salary, significantly decreased. Moreover, the crew numbers from vessel owners’ households significantly decreased. As a result, we discussed the changes, problems, regulations and restrictions related to trawl fishery in Foça, which used to be the most important trawling fishing center of the Aegean twenty years ago. We found dramatic changes in many aspects compared to what it was two decades ago and provided suggestions regarding fisheries management.
Bu çalışmada, Ege Denizi Foça'daki trol filosunun mevcut durumu ve tarihsel değişimi hakkında bilgi vermeyi amaçladık. 1998-1999 ve 2019 yıllarında aktif olarak çalışan tüm trol teknelerini temsil eden çalışmanın verileri, Foça'da bulunan trol teknesi sahipleri ile yüz yüze görüşülerek toplanmıştır. Anket; gemilerin özellikleri ve balıkçılık faaliyetleri, balıkçıların sosyo-demografik özellikleri, balıkçılık giderleri, türlerin yıllık karaya çıkış miktarları ve yönetim konuları ile ilgili sorulardan oluşmaktadır. Bu çalışma, hedef türlerdeki av miktarının son yirmi yılda önemli ölçüde azaldığını gösterdi. Balıkçılar, Dentex gibbosus, Dentex macrophthalmus, Homarus gammarus, Mustelus mustelus, Octopus vulgaris, Parapenaus longirostris, Scomber colias, Scorpaena porcus, Scorpaena scrofa, Spicara smaris, Trachurus spp. and Zeus faber gibi bazı türlerin karaya çıkışlarının bu dönemde dikkate değer bir düşüş gösterdiğini rapor etti. Aynı dönemde Merluccius merluccius, Lophius piscatorius ve Zeus faber gibi bazı türlerin ortalama boylarında da azalma görülmüştür. Gemilerin akaryakıt tanklarının hacmi ve operasyon süreleri 1999'dan 2019'a önemli artışlar gösterdi. Foça'nın trol filosunda 1999'dan 2019'a yaklaşık %75 azalma saptandı. Mevcut balıkçıların %55’i önümüzdeki 10 yıl içinde balıkçılık sektöründen ayrılabileceklerini bildirdi. Bu durum trol balıkçılığında paycılık sistemi geleneğini de değiştirmiş; maaş yerine pay olarak ödenen personel (mürettebat) sayısı önemli ölçüde azalmıştır. Ayrıca, tekne sahiplerinin hane halkından gelen mürettebat sayısı son yirmi yılda önemli ölçüde azalmıştır. Sonuç olarak, yirmi yıl evvel Ege’nin en önemli trol merkezi olan Foça’da günümüzde nasıl bir değişim olduğunu, sorunları, balıkçılık düzenlemeleri ve kısıtlamaları tartıştık. Yirmi yıl öncesine kıyasla birçok açıdan çarpıcı değişiklikler bulduk ve balıkçılık yönetimine ilişkin önerilerde bulunduk.
Understanding the spatiotemporal persistence of fish distributions is key to defining fish hotspots and effective fisheries-restricted areas (FRAs). Hierarchical Bayesian spatiotemporal models ...provide an excellent framework to understand these distributions, as they can accommodate different spatiotemporal behaviour in the data, primarily due to their flexibility. The aim of this research was to characterize the fundamental behavioural patterns of fish as persistent, opportunistic or progressive by comparing different spatiotemporal model structures in order to provide better information for marine spatial planning. To illustrate this method, the spatiotemporal distributions of 2 sympatric Mullidae species, the striped redmullet Mullus surmuletus and the redmullet M. barbatus, were analysed. The occurrence of each species, its conditional-to-presence abundance and median length were analysed using Mediterranean trawl survey data from the western Mediterranean between 2000 and 2016. Results demonstrate that there are various common hotspots of both species distributed along the Iberian coast. The convenient persistent spatiotemporal distribution of these hotspots facilitates the configuration of a network of connected FRAs for red mullets in the study area.
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The scale morphology of nine Mullidae taxa consisting of three genera and nine species from the Persian Gulf and the Gulf of Oman was described and compared using light and scanning electron ...microscopy from four different body regions. The general scale type in the studied mullid species was ctenoid except in the head region of Mulloidichthys vanicolensis and Parupeneus margaritatus, which had cycloid scales. The scales demonstrated a large focus with the central or centro‐posterior position. The large variations of scale morphology were observed for the scales from different body regions of a single species. The shape of focus was in five types with the round type being the most common. In the scales of most examined species, there were 5–6 radii present in the anterior field. No radii exist in the lateral and posterior fields, and the radii orientation was parallel in all the studied species. The rostral margin of scales represented five types among the studied species; waved (M. vanicolensis), smooth in (P. rubescens), dentate (Upeneus doriae), scalloped (U. vittatus), and fluted (U. tragula). The lepidont shape varied among the species from blunt to flat, pointed, tiny, sharp, pointed, triangle, short, and long. The results also showed that the relative scale size has a desirable contribution to separate the examined genera. The scale morphological‐based tree was largely consistent with the known systematics of the studied fishes. It was concluded that variation of scale characters has probably taxonomic and even phylogenetic information in both species and genus levels in the studied mullid fishes. However, variation of scale morphology between body regions, as shown in this study, suggests that scale characters should be used cautiously for taxonomic studies of these fishes.
The light and scanning electron microscopy techniques were used to evaluate the macro‐and microscopic characteristics of scale surface ornamentation in goatfishes.
The key scales were mainly of the ctenoid and sectioned type having a large focus with the central or centro‐posterior position.
The relative scale size has a desirable contribution to separate the examined genera.
The scale morphological‐based tree was largely consistent with the known systematics of the studied fishes.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The normal and lateral line scales from above the head and four flank regions were investigated in two goatfishes by using light microscopy to evaluate the microscopic characteristics of scale ...surface ornamentation from different body parts of these fishes and to add new morphological data for their discrimination. The body scales were removed and digital images captured with a Dino‐Lite digital camera connected to a Leica compound microscope. The presence of both transverse and longitudinal radii was a distinctive characteristic for the scales of studied goatfishes. The most distinctive features of the key scales discriminating the two goatfishes were the scale shape, the presence of irregular grooves in scale surface, the presence of transverse radii in the lateral fields, and the availability of lepidont at the anterior field. The lateral line scale ornamentations were almost similar in two species; however, the lateral line canal was branching in Parupeneus heptacanthus. Scale extension index indicated that in both species, the dimension of normal key scales tends to the right, while the dimension of lateral line scales tends to the left. This study accentuated that scales from different body regions may exhibit variation in surface ornamentations, that scale morphology could successfully be used to discriminate the examined goatfishes, and that the use of fish scale microscopy is an easy and relatively rapid method and does not require fish sacrifice. Since fish identification is essential for the conservation and management of species, the use of scale morphology to this purpose appears particularly promising.
This research work mainly highlights the significance of light microscopic observation while studying scale surface ornamentation of goatfish as it can further be used for taxonomic identification.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Lionfish Pterois volitans are successful invasive predators in the sub-tropical and tropical Western Atlantic. Their invasion of coral reef ecosystems is a major conservation concern, as previous ...studies in the Western Atlantic have found that this top predator (1) occurs at higher densities and forages more successfully than in its native range, (2) lacks significant predators as an adult, and (3) reduces reef fish recruitment. The effects of lionfish on coral reef communities have been examined, but it is not known if these predators use critical non-reef habitat such as mangroves, which serve as nurseries for many reef fish species. To investigate lionfish usage of non-reef critical habitat, we compared population size-structure and stomach contents of P. volitans in mangroves and coral reefs on the island of San Salvador, Bahamas. In each habitat, >80% of lionfish stomachs contained prey items with similar gut content wet weight (0.98 +/- 0.35 g in reef habitat and 0.99 +/- 0.43 g in mangrove habitat) despite differences in total lionfish length (231.1 +/- 10.30 mm in reef habitat and 176.3 +/- 16.83 mm in mangrove habitat). Prey items detected by genetic analysis included individuals of the families Palaemonidae, Penaeidae, Gobidae, Scaridae, Mullidae and Grammatidae. These results demonstrate that lionfish colonize and feed in mangrove habitat in the Bahamas. Further study of lionfish outside reef habitat is required to understand the effects of this marine invasion.
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Upeneus guttatus and Upeneus pori are the most common Mullidae species inhabiting the Gulf of Suez and mainly caught by the trawl fisheries. Reproductive biology of the two species was studied during ...the fishing period from September, 2013 to May 2015. The monthly gonad maturity development and the monthly gonado-somatic index (GSI) sequence of U. guttatus and U. pori revealed prolonged spawning activities throughout spring and summer seasons. The sex ratio was 1:2 for the two species in favor of females; it differed statistically from the expected 1:1 (X2=65.4 in U. guttatus and 70.4 in U. pori). The length at which 50% of the population attains sexual maturity (Lm50) is 11.35±0.32 and 11.47±0.25cm for males and females respectively in U. guttatus, where it was 10.56±0.21cm in males and 10.60±0.18cm in females of U. pori. Absolute fecundity increased as the fish length and weight increases. Observed absolute fecundity ranged from 142,925±5621 to 86,940±3364 eggs for the length range of 12.0–18.0cm in U. guttatus and from 8773±560 to 71,400±3219 eggs in total lengths of 11.0–16.0cm for U. pori, with a low value of standard error ranging between 0.28% and 4.9% in both species and high correlation coefficient (R2>0.96).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the Mediterranean Sea, six species of Mullidae have been recorded, four of them being alien to the area. The most recent arrival in the Mediterranean is the Red Sea goatfish (Parupeneus ...forsskali), which was first spotted there in the year 2000. Although P. forsskali is endemic to the Red Sea and the Gulf of Aden, it has recently expanded its distribution; it was confirmed in Cyprus in 2014. Since then, it has established a thriving population around the island, and is now commercially important. In the present study, the spawning season and gonad development of P. forsskali off the coast of Cyprus were studied, along with important biological parameters. Macroscopic and histological analyses of the gonads indicated five maturity phases for both ovaries and testes. The gonadal maturity phases and the gonadosomatic index indicated that P. forsskali spawns in the summer months, with the peak of the spawning season in July. Males were bigger, heavier, and more abundant than females, and the length-weight relationship was found to be TW=0.0065 TL3.17 for males and TW=0.0086 TL3.07 for females, both indicating positive allometric growth. The size at first sexual maturity (LM) was 14.2 cm for males and 11.8 cm for females. Five age groups were identified from the length-frequency distribution (0-4 years old). Age group 1 was the most dominant one, containing almost 60% of the sampled individuals. Natural mortality (M) declined with age, and the mean natural mortality coefficient across ages was 0.563 year-1. Overall, this is the first study that provides important information on the spawning season of the Red Sea goatfish and other estimations on various biological traits in its non-native habitat that can be of great importance for fisheries management.
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