RESUMEN
Grouper fish are among the most important components of the fisheries of many countries because they are found in warm water throughout the world. There are 15 genera and 159 species known worldwide; 8 genera and 66 species are exclusively found in the western Indian Ocean, Red Sea, and Arabian Gulf. The Summan grouper, Epinephelus summana, constitutes a considerable portion of these fisheries; therefore, this study aimed to evaluate the reproductive strategy of this important fish species. The fish samples were collected monthly for one year (from November 2020 to October 2021), and 217 fish were collected from the Red Sea of Jeddah, Saudi Arabia. The sex ratio, sexual maturation process, and spawning season were analyzed. Across all samples, landing consisted of 36.2 ± 4.7 % males, 64.0 ± 5.0 % females, and 3.4 ± 1.8 % transitional-stage fish, with an overall significantly different male-to-female sex ratio of 1:3.3. Furthermore, males were larger than females. The maturation index (MI), gonadosomatic index (GSI), and ovarian maturation rate (OMR) values fluctuated throughout the year, indicating that E. summana has extended spawning and spawns in batches during different months of the year. However, April to May is the main spawning season, with the highest female GSI recorded. Based on the microscopic histological examination of gonads, the maturation process can be classified into five stages in both males and females. In conclusion, this fish species has a complex reproductive biology. It undergoes sexual transformation and protogynous hermaphroditism, during which individuals mature first as female and then change sex to male. The obtained data is essential for successful fishery stock conservation, management, and aquaculture development.
RESUMEN
Schindleria parva, a new species of the family Schindleriidae, is described from two specimens collected from the central Red Sea of Saudi Arabia. The new species is characterized by lack of pigmentation on the body, possession of an inconspicuous gas bladder and the presence of small teeth on the premaxillae. The holotype is a female of 11 mm standard length (SL) (11.9 mm total length) and the paratype is a male of 9 mm SL. Dorsal fin rays 10 (9) anal fin rays 9 (7). The body depth at pectoral-fin origin 5% (4%) of SL, depth at anal-fin origin 8% (7%) SL, predorsal length 63% (65%) SL, preanal length 72% (72%) SL, the first anal-fin ray situated below the fourth dorsal-fin ray), a total of 23 + 16 myomeres. The female contained a series of 30 rectangular eggs in a single row, whereas the male is characterized by a short rod-like urogenital papilla. Species of the genus Schindleria are likely the smallest marine vertebrates on the planet and S. parva is likely the smallest Schindleria species in the Red Sea. The global diversity of Schindleria is likely underestimated due to the paedomorphic features of this genus. Its fast generation times make it a species-rich genus of high turnover rates, thus potentially highly important for the trophic food webs of coral reefs. Thus, this finding advances knowledge on the biodiversity of the Red Sea, highlights its conservation significance, and contributes towards the understanding of the complexity of the coral-reef fish community.
Asunto(s)
Peces , Perciformes , Animales , Arrecifes de Coral , Femenino , Océano Índico , Masculino , Arabia SauditaRESUMEN
Fishes of the family Lethrinidae form a considerable portion of the catch from both the Red Sea and the Arabian Gulf in Saudi Arabia, and the species Lethrinus lentjan (Lacepède, 1802) is one of the most important among these fishes. This study was conducted to evaluate the demographic structure coefficients, survival rate, and stock status of L. lentjan from the Red Sea coast of Saudi Arabia. A total of 593 samples were collected on a monthly basis for a period of one year from the landing site for fishing boats operating in Red Sea waters off Jeddah. The results indicated that 88.87% of the specimens were female; the maximum total length recorded was 43.5 cm with the most frequent length (14.67%) being 23-23.9 cm. The maximum age recorded for both males and females was 6 year-plus, and the 1 year-plus age category represented the majority of the samples (57.67%). The total mortality coefficient, natural mortality coefficient, and fishing mortality coefficient were 1.538, 0.315, and 1.223, respectively; all mortality coefficients in the female fishes were higher than those in the male fishes. The survival rate of males was higher (0.617) than that of females (0.214). The results of the present study indicate that L. lentjan is subjected to overfishing and a new management strategy is necessary to improve the stock status of this fish species.
RESUMEN
During a survey of demersal fishes of the southern Red Sea coast of Saudi Arabia off Jizan, 98 species were collected by trawling. Five of these represent new records for the Red Sea: Saurida longimanus, Dactyloptena gilberti, Jaydia novaeguineae, Pomadasys maculatus and Parapercis maculata. Additionally a specimen of the rare moray Gymnothorax reticularis, previously known from only three specimens, was collected. Records of two species, Parastromateus niger and Pseudorhombus arsius, that formerly were considered questionable, are confirmed by collection of new voucher specimens. Validity of Laeops sinusarabici is confirmed. This study documents parts of the diversity of the demersal fish communities on sandy areas of the southern Red Sea, but also emphasizes that a large proportion of this area has not been explored.