Size and weight estimations of the spangled emperor (Teleostei: Lethrinidae: Lethrinus nebulosus) from bone measurements elucidate the fishing grounds exploited and ancient seasonality at Akab (United Arab Emirates)

Abstract

The presence of emperor fishes has been reported in several archaeo-ichthyological studies in Eastern Arabia. The spangled emperor (Lethrinus nebulosus) is one of the main species currently composing annual landings in the central and southern Persian Gulf. Its presence outlines the importance of the coastal environments exploited during different life cycle stages, such as open-water reefs and sheltered embayments, including grass beds. Osteometrical methods for estimating the life-size from bones were developed during the last few decades. Measurements taken from the bones of 32 fresh spangled emperors, collected from a fish market in Umm al-Quwain (United Arab Emirates) in February 2017, were exploited to calculate regression equations (power fits), allowing size estimations from archaeological remains. Because of the difficulties in identifying emperor species using bones, we also tested and discussed the validity of a generic model.The Neolithic site of Akab has provided more than 37,000 fish remains, mostly belonging to kawakawa tunas, trevallies, and seabreams, which suggest that fishing was essentially carried out during the winter. Relatively few bones (totalling 100 measurements) were identified as belonging to spangled emperors. However, because of the ecological features of this species, estimated sizes permitted investigations into which fishing grounds were exploited, and even provided new evidence regarding ancient seasonality of coastal occupation in Eastern Arabia.

At the dawn of Arabian fisheries: Fishing activities of the inhabitants of the Neolithic tripartite house of Marawah Island, Abu Dhabi Emirate (United Arab Emirates)

“…c. Box plots of fresh weights for the main taxa identified (based on estimations according to visual comparisons with reference specimens) groupers, and cartilaginous fish). Several recent archaeo-ichthyological studies suggest that fishing could potentially have been carried out during a great part of the year as certain environments such as mangroves and reefs stay productive long enough (Beech, 2004: 201-207;Lidour & Beech, 2019;Lidour et al, 2018). Further investigations are, however, necessary to bring to light a possible sedentary lifestyle on the coast during the Neolithic (e.g.…”

Size estimation of pre‐Columbian Caribbean fish

“…As highlighted elsewhere (Cooke & Jiménez, ; Jiménez‐Cano & Masson, ; Lidour, Vorenger, & Béarez, ), working at the species level allows the finest application of ecological studies to document ancient fishing; however, the identification of fragmented archaeological bones is often difficult to differentiate at the species level. Consequently, allometric constants were calculated at the level of family, subfamily, genera, and species.…”

Strengths and weaknesses in the long‐term sustainability of two sympatric seabreams (Argyrops spinifer and Rhabdosargus haffara, Sparidae)

“…We observed a change in the length frequency distribution of landed A. spinifer at present compared to that in the past (mid‐17th to early 20th centuries) in the fact that the landings were contributed more by small‐sized individuals in recent years. Such a change was also observed in the spangled emperor Lethrinus nebulosus in the Gulf when comparing samples from 4600 to 4000 BC to present years (Lidour et al ., 2018). Relative lesser presence of large‐sized individuals in the landings could be attributed to multiple factors connected to fishery exploitation, such as variation and changes in major fishing gears (from hooks to traps and trawls; Al‐Mamry et al ., 2011), increase in fishing pressure leading to depletion of older cohorts (Bianchi et al ., 2000; Blanchard et al ., 2005) and regional differences in length frequency (Lin et al ., 2019a; Roa‐Ureta et al ., 2019b).…”