Search

Queen parrotfish Scarus vetula and stoplight parrotfish Sparisoma viride are widely distributed throughout the subtropical/tropical regions of the northwestern Atlantic, play important ecological roles in reef ecosystems, and contribute to small-scale commercial landings within several Caribbean management jurisdictions. Prior to this work, no comprehensive life history information existed for either species that combined otolith analysis and gonad histology. Queen parrotfish (n = 390) and stoplight parrotfish (n = 1801) were sampled throughout the U.S. Caribbean from 2013 to 2023. Queen parrotfish range in size from 82 to 402 mm FL and age from 0 to 16 years; stoplight parrotfish ranged from 73 to 433 mm FL and 0 to 20 years. Growth parameter estimates for queen parrotfish were L∞ = 347 mm FL and K = 0.42, when t0 was fixed to −0.06; for stoplight parrotfish, L∞ = 332 mm FL and K = 0.39, with a fixed t0 of −0.06. All female queen parrotfish transitioned to males by a maximum length and age of 322 mm FL and 14 years. In contrast, not all female stoplight parrotfish transitioned to males since the largest and oldest individuals sampled were females. Spawning capable queen parrotfish females were collected from November to August indicating a protracted spawning season of 10 months. Stoplight parrotfish exhibited year-round spawning with >50% of mature females in the spawning capable phase during all months of the year. Based on our overall findings related to life history, queen parrotfish and stoplight parrotfish in the U.S. Caribbean did not appear to exhibit signs of overexploitation which may in part relate to U.S. Caribbean management efforts currently in place that limit the minimum mesh size for traps (which ensures that smaller fish can escape from the traps), a ban on using gillnets to target parrotfish species, and the market driven targeting of "plate-size" fish by commercial spearfishers. The life history information documented in the current study will provide essential information for stock assessments and informed management in the U.S. Caribbean for these two important parrotfish species. [ABSTRACT FROM AUTHOR]

To ensure the success of genetic rescue, we must minimise the potential negative effects of outbreeding depression that may arise from selecting source populations. The difficulty in assessing the likelihood of outbreeding depression has hindered its consideration in endangered species conservation. However, genomic research offers feasible indications. Here, we conduct conservation genomic analyses on the East Asian (EA) population and the relict Western/Central Asian (WCA) population of the critically endangered Siberian crane (Leucogeranus leucogeranus). We aim to assess genetic rescue's potential advantages and disadvantages between the two populations. Our analysis shows genomic evidence of limited genetic differentiation between them. The persistent decline in population size due to historical climatic oscillations leads to a decrease in genetic diversity and an increase in inbreeding. The WCA population has excessive deleterious homozygous mutations than the EA population, suggesting suffering from inbreeding depression resulting from less effective purifying selection. Forward simulations support the increase in genetic load due to elevated levels of inbreeding compromises fitness during population collapse. We strongly recommend an urgent genetic rescue for the WCA population through population supplementation from the EA population. However, the continuous monitoring of fitness outcomes is required through captive breeding. This work provides useful insights into the genetic management of a critically endangered species and emphasises the importance of evaluating the likelihood of outbreeding depression through genomic approaches. [ABSTRACT FROM AUTHOR]

Aim: Recent literature is unveiling more complex responses of biodiversity to Pleistocenic climatic oscillations than those derived from initial models based solely on southern glacial macrorefugia. Here, we zoom in to delve into the genetic diversity and population structure of Podarcis lusitanicus, a lizard species native to the north‐western Iberian Peninsula. Location: North‐western Iberian Peninsula. Taxon: Podarcis lusitanicus. Methods: Utilising a comprehensive multilocus approach, we explored the species' phylogeography and demographic history at a very fine spatial scale and timeframe. Concurrently, we evaluated both current and historical habitat suitability for the species, linking it to the observed demographic trends. We examined DNA sequences from two mitochondrial (cytb and ND4) and three nuclear genes (ACM4, MC1R and PDC) in 230 specimens collected from 21 populations spanning most of the species' distribution range. Results: Our findings corroborate cytonuclear discordances in Podarcis, with nuclear genes failing to identify the mitochondrial clades in P. lusitanicus. Despite its separation from other Podarcis species approximately 4 million years ago, its diversification occurred much more recently, around 0.4 million years ago, resulting in three monophyletic lineages that are geographically coherent. This pattern suggests that some lineages of P. lusitanicus might have gone extinct after the split from the common ancestor. Pleistocene climatic oscillations profoundly influenced the demographic history of the species. During warmer periods, such as the Last Interglacial, populations expanded and came into secondary contact, whereas during the Last Glacial Maximum, populations contracted and became isolated in multiple micro‐refugia. The subsequent Mid‐Holocene warming facilitated population recovery, range expansion and lineage admixture. Main Conclusions: This study underscores the intricate interplay between isolation and dispersal at a microscale, driven by Pleistocene climatic fluctuations, which have profoundly shaped the genetic structure and diversity of Iberian terrestrial biodiversity and may remain overlooked by biogeographic studies at coarser scales. [ABSTRACT FROM AUTHOR]

ABSTRACT Understanding population demography of threatened species and how they vary in relation to natural and anthropogenic stressors is essential for effective conservation. We used a long‐term photographic capture‐recapture dataset (1993–2020) of Indo‐Pacific bottlenose dolphins (Tursiops aduncus) in the highly urbanised Adelaide Dolphin Sanctuary (ADS), South Australia, to estimate key demographic parameters and their variability over time. These parameters were analysed in relation to environmental variables used as indicators of local and large‐scale climatic events. Our findings indicate that apparent survival was high (0.98–0.99) and did not vary seasonally. Estimates of abundance were not directly related to environmental variables but were linked to seasonal temporary emigration. Abundance peaked in summer with an average of 85.37 dolphins (SD = 30.23) and was lowest in winter, with 68.57 (SD = 24.70) individuals. Site fidelity at the population level was low, but lagged identification rates revealed a population of approximately 28 individuals at any one time. Trend analysis suggests an increase in dolphin abundance from 1993 and persistence of the population over decades despite significant urbanisation, although numbers have declined in more recent years. Further research is needed to understand the cumulative impacts leading to this population decline and to assess its future viability under different management scenarios. Conservation strategies aimed at increasing reproductive rates and promoting connectivity to adjacent waters are likely to be more effective in reversing population declines.