Abstract Marine community science presents an important route to gather valuable scientific information while also influencing local management and policy, thus contributing marine conservation efforts. Because seahorses are cryptic but charismatic species, they good candidates for engaging diverse people help overcome the many gaps in biological knowledge. We have synthesized contributed project iSeahorse from October 2013 April 2022 35 of 46 known seahorse species. then compared obtained...

Anthropogenic pressures on marine ecosystems are increasing worldwide, causing loss of biodiversity and ecosystem functioning, driving species towards risk extinction. To protect vulnerable habitats, Marine Protected Areas (MPAs) increasingly established worldwide as conservation measures. Seahorses act flagship for coastal due to their charismatic appearance high vulnerability habitat degradation. Here, the suitability two European seahorse species, Hippocampus hippocampus guttulatus, was...

ABSTRACT Community science provides a valuable approach for population monitoring, offering benefits such as public engagement, cost‐effectiveness and broad geographic coverage. Seahorses are excellent candidates community monitoring because they iconic sedentary their cryptic nature patchy distribution hampers formal professional research. We analysed data collected by non‐profit organization the iSeahorse programme. Data were members over 5‐year period in two locations Tampa Bay, Florida,...

Comparisons of three sets surveys in the Ria Formosa Lagoon, Portugal, over a 13 year period (2001–2002, 2008–2009 and 2010–2013) revealed significant population fluctuations at least one two seahorse (Hippocampinae) species living there, that those were potentially associated with habitat changes lagoon. After decline between first survey periods (2001–2002 v. 2008–2009), long‐snouted Hippocampus guttulatus populations increased significantly new 2010–2013 surveys. There no differences H....

Accurate taxonomy, population demography, and habitat descriptors inform species threat assessments the design of effective conservation measures. Here we combine published studies with new genetic, morphological data that were collected from seahorse populations located along European North African coastlines to help management decisions for seahorses. This study confirms presence only two native (Hippocampus guttulatus H. hippocampus) across Europe, sporadic occurrence non-native in...

Changes in water temperature may have profound effects on physiology, metabolism, and fish behaviour. However, much of the existing research is based relatively short-term experiments. In context climate change, where temperatures are increasing seasonally, frequency duration extreme heatwave events rising, incorporating longer exposure periods will provide a better understanding potential warming marine species. Here, we tested prolonged to elevated broad-nosed pipefish, Syngnathus typhle....

Temperature is a determinant cue for several behavioral, physiological, and metabolic processes in fish, which occur within range set to optimize species fitness. Understanding how ocean warming will impact species, at individual population levels, is, therefore, of utmost relevance management conservation purposes. This knowledge assumes particular when it comes with unique life history traits that experience multiple threats, such as seahorses. study aimed assess the effects on growth,...

In this study, the spot pattern in Hippocampus guttulatus was analysed using a computer programme algorithm that allowed individual comparison. This methodology first tested controlled environment 51 adult and 55 juvenile H. . Positive matches were obtained 86·3 83·6% of adults juveniles, respectively. second experiment, monthly surveys carried out five selected locations Ria Formosa Lagoon, south Portugal, over course year total 980 photographs analysed. Photographed re‐sighted one to nine...

Abstract After seahorse population fluctuations were revealed in previous studies, probably due to changes their natural habitat, this study sought determine the current status of populations two existing species Ria Formosa lagoon, by revisiting previously surveyed sites, while assessing main drivers for detected changes. Hippocampus guttulatus densities decreased significantly between 2002 and 2008, followed a significant increase 2008 2012 decrease 2018. There no differences H. surveys,...

This study investigated the effect of partially replacing fish meal with krill and copepod meals in inert diets, co-fed shrimp, on growth nutrient digestibility long-snout seahorse (Hippocampus guttulatus). A control diet (Diet 1) using raw starch four experimental diets similar protein (≈44.8%) energy (≈15.1 MJ/kg) levels were tested. Diet 2 used as sole source, while Diets 3-5, replaced 44% meal. Seahorses fed Shrimp + 2-5 showed significantly higher rates (P < 0.05) than those...

Artificial marking and tagging techniques have been used to study movement, population dynamics, behaviour, ecology, survival growth of at least 25 syngnathid species. External necklace-style tags injection visible implant elastomer the most techniques, uniquely identifying hundreds individual syngnathids mortality, ecology in 13 12 species, respectively. Only two studies, both on larger tested use internal or electronic tags. This new case reveals that dummy tags, weighing up 6% body mass,...

Abstract This study evaluated the effects of underwater noise as a source acoustic stress in wild populations Hippocampus guttulatus Ria Formosa, south Portugal. Two different scenarios were tested: transient motor boat sound (63.4–127.6 dB) and constant produced by directly above animals (up to 137.1 dB). Observations obtained between 4 10 m depth throughout 3 min period, using video camera hydrophone set, compared with control sample. A significant increase ( P < 0.05) respiratory rate...

This investigation examined the effects of temperature, density and early weaning on survival growth Palaemonetes varians larvae. Survival larvae raised at 17.5 °C was not significantly different (average + standard deviation) (94 ± 5%) from those 19.5 (95 21.5 4%). However, duration larval stage longer for shrimp reared (17.3 0.8 days) compared with (14.3 0.7 (11.3 0.6 days). No significant differences (P>0.05) were found in rate, final weight length densities 5, 10, 20 50 L−1. The P. fed...

This investigation examined the effect of prey condition on growth and survival juvenile cuttlefish (Sepia officinalis). In first group, were fed with daily captured live Palaeomonetes varians from wild [daily (DP)], second group was 5 days stocked starved P. [starved (SP)], while in third 8 an artificial diet [fed (FP)]. Mean instantaneous rate (IGR) 2.8±1% body weight day−1 (bw day−1), 3.3±1.1% bw 4.9±0.5% for SP, DP FP respectively. At end experiment, final gain (Wg) 121±21.6%,...

The present study was carried out in the marine area of Stratoni, Greece, where two seahorse species are (Hippocampus hippocampus and Hippocampus guttulatus). Two surveys were conducted (September 2016 May 2019) to gather information regarding species' abundance, distribution habitat characteristics. Four different natural artificial types identified. results revealed that presence H. relatively high, especially at sites with structures, whereas guttulatus rare. Data collected can provide...

This investigation examined the effects of live prey availability on growth and survival Sepia officinalis. Two independent experiments, comprising two feed rations each, were performed, using adequate size. In first experiment, cuttlefish hatchlings fed mysids, Paramysis nouvelli [(feed ratio I (fr I)], at 15% body weight per day (bw day−1) I15) 30% bw day−1 I30). second juvenile Atlantic ditch shrimp, Paleomonetes varians II), under same experimental design. both final mean weight, feeding...

The deployment of Artificial Holdfast Units (AHU) has been demonstrated as an effective tool for creating holdfast and sheltering conditions Hippocampus guttulatus in the Ria Formosa (South Portugal). Preliminary results obtained with a pilot-scale AHU showed high settlement rate, recorded densities up to 13.1 individuals.m -2 . With present study, we aim understand weather AHU’s contributed attract new H. recruits or concentrate those previously existing these areas. Prior total four focal...