The narrow-barred Spanish mackerel, Scomberomorus commerson, is a highly valuable commercial species in the Red Sea. Annual landings along the Saudi Arabian Red Sea coast average approximately 2, 380 tonnes, generating nearly 35 million USD in revenue. Given this economic importance, effective fishery management is essential. This study assessed the growth, maturity, and mortality of S. commerson using fishery-dependent samples collected from the eastern Red Sea between 2022 and 2024. Total length (L, n = 4, 432) ranged from 10.0 to 151.0 cm, and total weight (W, n = 1, 683) varied from 9 to 17, 694 g. L–W relationships were W = 0.0088 × L2.90 for females and W = 0.0143 × L2.78 for males. The von Bertalanffy growth parameters, estimated via otolith reading, were L∞ = 151.55 cm, K = 0.18 year−1, and t0 = −0.83 years. Median length at first maturity was 39.71 cm, with no significant difference between sexes. Mean natural mortality rate, averaged across three empirical models, was 0.27 year−1. Total mortality rate, derived from a linearized decay model, was 0.58 year−1, giving a calculated fishing mortality rate of 0.31 year−1. Virtual population analysis provided age-specific fishing mortality rates as input for yield-per-recruit and spawning potential ratio (SPR) analyses. SPR analysis revealed that the current fishing pattern has reduced the spawning stock biomass to approximately 25% of its unfished level. The exploitation rate was 0.53, exceeding the limit reference point of 0.5. The fishery, dominated by handlines and gillnets, captures individuals across a broad size range, with immature fish comprising 17% of total landings. Most juveniles are taken incidentally as bycatch in the shrimp-trawl fishery. To promote stock recovery and long-term sustainability, management measures are recommended, including a 40% reduction in fishing effort, seasonal closures during spawning periods, and improvements in gear selectivity to minimize juvenile catch.

Ports and marinas are global hotspots for non-indigenous species (NIS), yet biofouling communities in the Arabian Gulf remain poorly documented. Here, we present the first spatially extensive assessment of biofouling communities along ~ 300 km of the Saudi Arabian Gulf coastline. Across 12 sites, we combined COI metabarcoding of scrapings from pontoons/docks and settlement panels with image-based analysis of same panels to characterize taxonomic composition and quantify native, cryptogenic, and non-indigenous taxa. Community analyses revealed a clear site-level differentiation across all datasets, while broader geographic locations and environmental risk categories explained little variation. DNA metabarcoding detected more taxa than visual analyses, including 57 cryptogenic and NIS, many of which could not be visually detected. Industrial and commercial ports harbored higher NIS richness and relative abundance than recreational marinas, indicating localized invasion risk. Despite the sensitivity of DNA-based approaches, species-level assignments must be interpreted cautiously due to sparse regional reference libraries and limited representation of Gulf taxa in global databases. By generating one of the first spatially explicit baselines of biofouling biodiversity and NIS in the northwestern Indian Ocean, our study underscores the urgent need to expand region-specific reference databases and to implement integrated, site-resolved monitoring frameworks to support emerging marine biosecurity programs across this understudied system.

Population structure is a key consideration for the management of exploited marine fishes, particularly for highly mobile species. The narrow-barred Spanish mackerel (Scomberomorus cf. commerson), also known as kingfish, sustains major fisheries in the Red Sea and Arabian Gulf, yet its genetic structure across these regions remains unknown. This study addresses this gap by assessing the genetic diversity and population structure of 105 individuals of S. cf. commerson sampled from seven localities across the Red Sea and Arabian Gulf. Integrating results from two mitochondrial (COI and D-loop) and 16 microsatellite markers, we observed a high genetic diversity and overall genetic homogeneity across the study area, suggesting strong gene flow across the region. Nonetheless, low but statistically significant genetic differentiation was detected between the Red Sea and Arabian Gulf, a pattern common in marine fishes. These findings suggest that S. cf. commerson forms a connected population with weak spatial structure in the Northwestern Indian Ocean, providing essential genetic evidence for fisheries management to support effective conservation and long-term sustainability of this important fishery resource.

A species of octopus from the Red Sea is described based on two recently collected fisheries survey specimens and four historical specimens housed in the Natural History Museum, Vienna. The latter were collected between 1895 and 1927, including specimens from two of the Austrian Pola Expeditions of the late nineteenth century. This species is here identified as Pinnoctopus cuvierii (d’Orbigny, 1826) which is redescribed based on morphological characters and comparison with the monotypic holotype of P. cuvierii, that of congeneric species P. lechenaultii (d’Orbigny, 1826) and, from the Mediterranean Sea, a voucher specimen of P. macropus (Risso, 1826). The distributions of P. cuvierii (an Indian Ocean species) and P. macropus are separated by the barrier between the Red Sea and the Mediterranean Sea, with no evidence of any distribution overlap after the opening of the Suez Canal. The first molecular reference sequences are provided for P. cuvierii including one nuclear and four mitochondrial genes. Phylogenetic analysis and comparison with other species in the same genus reveal that P. cuvierii is most closely related to the Indo-West Pacific species P. luteus (Sasaki, 1929) and relatively distantly related to P. macropus, which has closer affinities to the Atlantic species P. furvus (Gould, 1852).

This study presents updated biological and stock assessment information for two coral groupers, Plectropomus areolatus and Plectropomus marisrubri, in the Eastern Red Sea. A large sample collected from nine landing sites provided new estimates of growth, maturity, mortality, and exploitation, derived from otolith ageing, length–weight relationships, and yield-per-recruit and spawning potential ratio analyses. The two species showed distinct life-history patterns, with P. areolatus maturing earlier and exhibiting faster growth. Both species were found to be overexploited under current fishing pressure, with spawning biomass reduced well below commonly used sustainability thresholds. These results indicate that reductions in fishing mortality are required to rebuild reproductive capacity, particularly for P. areolatus. Management actions, such as increasing hook selectivity and enforcing minimum landing sizes, are supported by the observed maturity schedules. Seasonal protection of spawning periods is consistent with the low spawning potential ratios. This study provides the first recent age-based assessment for these two species in the region, offering a biological basis for species-specific management planning in the Eastern Red Sea.

Penaeus semisulcatus is the dominant commercial prawn species along the Saudi Arabian coast in the southeastern Red Sea, yet its population dynamics remain poorly understood. This study examined growth, maturity, and mortality using fishery-independent samples obtained during trawl surveys off Jizan and Al Qunfudhah between October 2022 and September 2023. A total of 85,909 individuals were examined, exhibiting carapace lengths (CL) between 1.29 and 56.14 mm and weights (W) ranging from 0.91 to 94.99 g. The sex ratio (1:1.06) was slightly male-biased. The CL–W relationships were W = 0.00427·CL2.50 for females and W = 0.01274·CL2.16 for males. The von Bertalanffy growth parameters were CL∞ = 60.16 mm, K = 1.03 year−1 for females and CL∞ = 48.10 mm, K = 1.02 year−1 for males. Females first matured at a CL of 22.09 mm. Exploitation rates (0.63 for females and 0.69 for males) and spawning potential ratio analysis indicated severe overfishing, with spawning stock biomass reduced to 19% of its unexploited level. These results highlight the necessity for immediate management intervention. Reducing fishing effort by half, extending seasonal closures, and improving the selectivity of trawl gear are advised to facilitate stock recovery and support sustainable exploitation in the region.

This study aims to enhance our understanding of the marbled spinefoot (Siganus rivulatus) population along the Red Sea coast of Saudi Arabia. It investigates whether the stock is subject to overfishing and tests the hypothesis that current fishing mortality exceeds sustainable thresholds. A total of 6192 specimens were sampled during a comprehensive survey conducted from 2022 to 2024, utilizing a range of fishing methods, including handline, trap, gillnet, and demersal trawl fisheries. The sampled fish ranged in total length (TL) from 100 to 335 mm and in total weight (W) from 17 to 470 g. The length–weight relationship was W = 0.0175 × TL2.92. Growth parameters derived from the von Bertalanffy model were TL∞ = 43.5 cm, K = 1.12 year−1, and t0 = −0.18 year. The median size at first maturity was estimated at 14.83 cm TL for both sexes. Virtual Population Analysis revealed fishing mortality rates ranging from 0.01 year−1 to 0.89 year−1 across age classes 1 to 5 years, with exploitation levels of 0.6, 0.55, and 0.5 at ages 3, 4, and 5, respectively, indicating slight overfishing. The annual average catch of marbled spinefoot along the Saudi Arabian Red Sea coast was approximately 211 tonnes, contributing an estimated 1.8 million USD to the national economy. Maintaining the current fishing effort at sustainable levels is essential to ensure the long-term viability of this stock.

Metapenaeus monoceros is the second most abundant commercially important shrimp species caught along the Saudi Arabian Red Sea coast. However, knowledge of its life history and population dynamics in the region remains limited, posing challenges for sustainable management. This study assessed the growth, maturity, and mortality of M. monoceros based on fishery-independent samples collected from shrimp trawling grounds off Al Qunfudhah and Jizan (October 2022–September 2023). Altogether, 10,859 specimens were examined, with a carapace length (CL) ranging from 7.98 to 49.10 mm and a total weight (W) in the range of 0.41 to 41.28 g. The observed sex ratio was 1.56:1 in favor of females. The CL–W relationship was W = 0.0024∙CL2.58. The seasonalized von Bertalanffy growth parameters were CL∞ = 50.66 mm, K = 0.35 year−1, tanchor = 0.43 years, C = 0.64, and ts = 0.61 years for females, and CL∞ = 38.97 mm, K = 0.55 year−1, tanchor = 0.51 years, C = 0.84, and ts = 0.39 years for males. Females reached their first sexual maturity at 21.12 mm CL. The exploitation rates (0.60 for both sexes) indicated overfishing. Spawning potential ratio analysis showed that the current fishing pressure reduces the spawning stock biomass to 23% of unexploited levels. A 50% reduction in fishing effort, extended seasonal closures, and selective gear modifications are recommended to rebuild the stock and ensure sustainability.

This study evaluates the stock status of Scomberomorus commerson in the southern Arabian Gulf, particularly in Abu Dhabi waters, using length-based models to address data limitations in fisheries assessments. The findings contribute critical insights into management practices using four length-based models, namely, LBI, LBB, LBSPR, and LIME, to analyze length frequency distributions from commercial catches between 2011 and 2023. The results indicate that the stock is overfished, with low proportions of mature and optimal-sized individuals and an excessive harvest of juveniles, as shown by the model estimates of F/M ratios and SPR values below target levels. From 2011 to 2019, the biomass declined sharply, but signs of recovery were evident by 2023 due to management actions, such as a gillnet ban introduced in 2019. The final-year estimates revealed a B/Bmsy ratio of 1.0 and F/M of 1.2, suggesting ongoing but reduced overfishing pressures. These outcomes underscore the importance of ongoing data-limited assessment methods in monitoring exploited stocks, providing evidence that restrictive measures have positively impacted biomass recovery. The convergence of outputs across methods, such as the indication of overfishing in S. commerson stocks, suggests that implementing multiple models enhances the robustness of management recommendations, including the enforcement of minimum size limits or reductions in fishing efforts or restriction of certain fishing methods. Overall, this study highlights the importance of using multiple models and choosing appropriate priors to improve the quality of stock assessments in data-limited fisheries.

The yellow-edged lyretail grouper, Variola louti, is ecologically and commercially important in the Red Sea. As a carnivorous species, V. louti plays a vital role in maintaining coral reef ecosystem health. Annually, an estimated 260 tonnes of V. louti are landed along the Saudi Arabian Red Sea coast, contributing approximately 6.5 million USD to the national economy. Given its significance, effective fishery management is crucial for sustainability. This study assessed the growth, maturity, and mortality of V. louti using fishery-dependent samples collected from the eastern Red Sea (February 2022–December 2024). Fork length (FL, n = 7,087) ranged from 10.5 to 64.3 cm, while total weight (W, n = 2,629) varied from 53 to 2,910 g. The FL–W relationship for both sexes combined was W = 0.0117×FL3.1. Von Bertalanffy growth parameters, based on sagittal otolith readings, were FL∞ = 62.28 cm, K = 0.12 year−1, and t0 = −2.26 years. Median FL at first maturity was 24.98 cm, with no significant sex differences. Mean natural mortality (M), derived from three different methods, was 0.243 year−1. Total mortality (Z), estimated using a linearized exponential decay model, was 0.38 year−1. Based on these Z and M estimates, fishing mortality (F) was calculated as 0.137 year−1. Yield-per-recruit and spawning potential ratio analyses indicate that the current F estimate places the stock near the target reference point. The current exploitation rate (E = 0.36) remains well below the limit reference point of 0.5. The V. louti fishery encompasses a broad FL range and multiple age groups, with immature individuals comprising less than 12% of total landings. However, according to the minimum landing size of 33 cm FL set by Saudi Arabian fisheries regulations, 47% of the total catch consisted of mature fish aged 2–3 years but below this threshold (25 cm ≤ FL < 33 cm), while only 41% met the legal-size requirement (FL > 33 cm). The high proportion of legally undersized individuals in landings underscores the need for ongoing monitoring and additional management measures, such as catch quotas, seasonal restrictions, and fishing effort reduction, to ensure long-term stock sustainability.

ABSTRACT The narrow‐barred Spanish mackerel, Scomberomorus commerson, is an economically important fish species in the Arabian Peninsula. This study aims to revisiting its life history traits by data collected in a 15‐month monitoring program (January 2019–May 2020) in UAE waters. Fork length ranged from 30.5 to 132 cm. Growth parameters of k were 0.14 and 0.15, Linf was 128.9 and 135.4 cm, and t0 was −2.4 and −2.3 for males and females, respectively. The Lm50 were 78.7 and 69.7 cm FL, and Am50 were 2.0 and 1.8 years for females and males, respectively. Gonadosomatic index showed that the spawning season had started in March and ended in June with a clear peak in April. Mortality estimates were 0.69 year−1 for total mortality, 0.43 year−1 for fishing mortality, and 0.26 year−1 for natural mortality. The mean size and age at first capture were 43.4 cm FL and 1.8 years, respectively. The spawning biomass ratio was estimated at 20.5%. In the study period of 2019–2020, high exploitation rate especially on juvenile fish capture was recommended to reduce for long‐term sustainability.

Length–weight relationship (LWR) for the Red Sea roughy, Hoplostethus marisrubri Kotlyar, 1986 [Trachichthyiformes: Trachichthyidae], collected with a commercial shrimp trawler (n = 136) off Yanbu in the Red Sea at depths ranging between 662 and 667 m, is presented herein. Hoplostethus marisrubri can be distinguished by a combination of characters: dorsal-fin rays V–VI, 13; pectoral-fin rays 14–15; anal-fin rays II–III, 9; predorsal scales 19–20; distinctly enlarged lateral-line scales; and the dorsal fin without a black outer edge. In our study, a new maximum standard length of 130 mm was recorded. We estimated the length–weight relationship (LWR) parameters a and b for H. marisrubi as 0.033 and 3.17, respectively, which are new additions to FishBase. Based on the b value of the LWR, H. marisrubi has a positive allometric growth.

Newly collected specimens of two Red Sea endemic shrimps, Pleoticus steindachneri (Balss, 1914) and Parapenaeus fissuroides erythraeus Crosnier, 1986, allow their taxonomic status to be revised based on a molecular analysis. Results of DNA barcoding comparison synonymize P. fissuroides erythraeus with P. indicus Crosnier, 1986. The poorly known Pl. steindachneri is re-described and illustrated. Molecular phylogenetic analysis on Pl. steindachneri reveals that Pleoticus Spence Bate, 1888 is polyphyletic. Pleoticus steindachneri is herein transferred to Solenocera Lucas, 1849, and Faxonia Bouvier, 1905 is revived for Pl. robustus Smith, 1885. A modified key to the genera of the family Solenoceridae Wood-Mason in Wood-Mason & Alcock, 1891 is provided.

The common seahorse, Hippocampus kuda, is widely distributed throughout the Indo-Pacific region, occurring from East Africa to Hawaii, where it typically inhabits diverse ecosystems such as estuaries, lagoons, coastal zones, and seagrass beds. Despite its extensive geographic range, reports of its occurrence in the Red Sea remains limited, primarily restricted to the northern region of the Red Sea. Here, we report a new distributional record of H. kuda in Saudi Arabian waters within the south-central Red Sea. A single female specimen of H. kuda was collected through trawling conducted off the coast of Al Qunfudah at depths ranging from 15 to 20 meters. Morphological and molecular examination confirmed the identity of the specimen as H. kuda. The new record of H. kuda represents the second occurrence of this species in south-central Red Sea and expands its known distribution range 367 kilometers further south than the first reported record off Jeddah in 1838.

Shrimp trawl fishery is of significant importance in Saudi Arabia’s marine capture fishery sector. Al Qunfudhah and Jizan are the only ports along the southern Saudi Arabian coast of the Red Sea dedicated to shrimp fishing. This study evaluates the catch per unit effort (CPUE) of targeted shrimp species along with the associated retained bycatch and discard ratios across these two trawling locations. Using daily catch data from commercial shrimp trawlers specific to each port’s vessel type, this research provides the first comprehensive analysis of CPUE dynamics and fishing practices in these fishing grounds. The CPUE of target shrimps exhibited a wide range (0.01 kg h−1 to 13.08 kg h−1) with an overall mean of 1.37 ± 0.143 kg h−1. Penaeus semisulcatus emerged as the predominant species (mean CPUE: 3.77 ± 0.28 kg h−1), followed by Metapenaeus monoceros (mean CPUE: 0.1 ± 0.02 kg h−1). Significant differences in CPUE were observed among species, including P. semisulcatus, Penaeus hathor, and Penaeus pulchricaudatus, although CPUE differences between the two fishing grounds were minor, likely due to their proximity and similar environmental conditions. The bycatch analysis identified a total of 72 species across 28 families, with significant variation in the relative ratios. Sepiidae species constituted 31.8% of the total bycatch, followed by Portunidae species (24.8%). Discard patterns also varied, with Gerres oyena being the most commonly discarded species (mean discard ratio: 11.37% ± 1.89%), followed by Equulites klunzingeri (mean discard ratio: 8.76% ± 2.00%). While CPUE differences between Al Qunfudhah and Jizan were modest, this study highlights the need for expanded spatial and temporal coverage to enhance future analyses. These findings underscore the importance of integrated data for a comprehensive understanding of fishing effort and bycatch dynamics, supporting sustainable fisheries management in the Red Sea. By addressing bycatch and discard practices, this research contributes to efforts to mitigate ecological impacts and promote sustainable resource use in Saudi Arabia’s fisheries sector.

The Tetraodontiform family Triacanthidae Bleeker, 1859 is recorded for the first time from the Red Sea. Fishing experiments employing a commercial shrimp trawler off Jizan, Saudi Arabia, revealed species occurrences of short-nosed tripodfish, Triacanthus biaculeatus (Bloch, 1786) at depths ranging from about 11 to 34 m. Currently, this species has only been found in shallow sandy/muddy habitats in the southern Red Sea. Further surveys are imperative to demonstrate the actual distribution of short-nosed tripodfish across a wider range of environmental gradients along the Red Sea.

This study assessed catch composition, size selectivity, and fishing efficiency of demersal trawls targeting penaeid shrimp species in the Red Sea. It first compared the currently used diamond mesh codends in two fishing areas, Al Qunfudhah and Jazan, and then compared alternative square mesh codends to diamond mesh codends in Jazan. A total of 33 valid hauls were conducted in 2023, yielding 10,869 kg of total catch. The results showed that the square mesh codend significantly improved size selectivity, particularly for Penaeus semisulcatus and Metapenaeus monoceros, with L50 (50% retention length) values closer to their size at first maturity. The fishing efficiency indicators revealed a reduced retention probability for undersized individuals with square mesh codends. Additionally, bycatch discard rates decreased, indicating potential benefits for ecosystem conservation. This study suggests incorporating square mesh codends into fishery management regulations to enhance size selectivity and reduce bycatch during Red Sea shrimp trawling. Establishing a legal minimum landing size requirement is recommended to complement these efforts and promote sustainable fishing practices.

A single specimen of Indian Zebra Sole, Zebrias synapturoides (Jenkins, 1910) was trawled off Al–Qunfudhah, which is being reported herein as a new record for the Red Sea. This species is characterized by (1) the presence of three bars on head and by the (2) dorsal and anal fins joined to the basal portion of the caudal fin. Zebrias synapturoides is widely distributed in the Indian Ocean and the paucity of its record in the Red Sea could be attributed to the inadequate sampling efforts in the shallow sandy habitats.

The Mediterranean Large Elasmobranchs Monitoring (MEDLEM) database contains over 3000 records (more than 4000 individuals) of large elasmobranch species from 20 different countries around the Mediterranean and Black seas, observed from 1666 to 2017. The main species included in the archive are the devil fish (1 813 individuals), the basking shark (939 individuals), the blue shark (585 individuals) and the great white shark (337 individuals).In the last decades other species such as the shortfin mako (166 individuals), the spiny butterfly ray (138) and the thresher shark (174 individuals) were reported with an increasing frequency. This was possibly due to an increased public awareness on the conservation status of sharks, and a consequent development of new monitoring programmes. MEDLEM does not have a homogeneous reporting coverage throughout the Mediterranean and Black seas and it should be considered as a database of observed species presence. Scientific monitoring efforts in the south-eastern Mediterranean and Black seas are generally lower than in the northern sectors and the absence in our database of some species does not imply their actual absence in these regions. Some considerations are made on the frequency and spatial distribution of records, size structure of the observed individuals for selected species, general area coverage and species involved as by-catch by fishing gear.