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Ibacus peronii were captured, tagged and released off the east coast of Australia during 1993 and 1994 to study their patterns of growth and movements. Ten long-term recaptures have been reported since 1996, representing the longest recorded times at liberty for any tagged Scyllarid lobsters. Times at liberty for these 10 animals ranged between 1802 and 3417 days. Growth increments for all recaptured animals were within the ranges expected from shorter term recaptures, and all were recaptured from the same areas where they were tagged. These long-term recaptures reinforce previous conclusions on growth and movements of I. peronii, and are important in demonstrating to fishers and fishery managers that they are long-lived, do not move long distances and are susceptible to overfishing. The ratio of all recaptured tagged male and female I. peronii since 1993 was approximately 3:2. However, there were no differences in the recapture rates of males and females for small (less than 65 mm carapace length (CL)) and large (≥65 mm CL) individuals at tagging. The overall skewed recapture rate between sexes is likely to have been due to females being, on average, larger than males at the time of tagging and tag-loss being greater in these larger animals. These long-term recaptures show that, when properly inserted, the standard Hallprint T-bar tags used are retained through moulting events for many years. [Copyright &y& Elsevier]

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Simple Summary: Animals that are capable of suffering from pain and distress should be protected when they are being submitted to circumstances that could provoke suffering, such as experimental surgery or killing for human consumption. In terrestrial animals used for scientific purposes and food production, evidence of their capacity to experience pain has led to their legal protection. Recent studies have suggested a pain-like experience in decapod crustaceans. As a consequence, the UK Government has recently recognized decapods as sentient beings. Similarly, some countries have imposed recommendations for the handling, transport, and stunning prior to killing of decapods (Australia, New Zealand, Norway, and Switzerland), acknowledging that suffering during slaughter has a high risk for their welfare. Drugs and methods that may act as anesthetics rendering crustaceans unconscious as well as analgesics or pain-relievers are reviewed here, and other non-decapod crustaceans such as amphipods, brachiurids, branchiopods, copepods, ostracods, and isopods are also included. We developed a detailed on-line tool available publicly that scientists and other stakeholders can employ to search for the most effective methods that effectively anesthetize different crustacean species. This novel tool will also help to identify gaps in existing knowledge so that new drugs or species can be explored in future studies. Methods to induce analgesia and anesthesia for research purposes, handling, transport, or stunning have been used in 71 species of crustaceans. A non-systematic literature search was conducted on crustacean anesthetic methods. This review presents a comprehensive evaluation of drugs and non-chemical methods used to provide analgesia and anesthesia in many crustacean species rather than just decapod crustaceans. This information allows users to select an appropriate method or agent for their species of interest. We prepared an on-line tool based on datasette, a no-code open-source solution for simple web-based database frontends that allows exploration and downloading data by method, analgesic/anesthetic, species, life stage, or sex, as well as other data including environmental conditions (temperature, salinity, light), route of administration, dosage, and induction and recovery times. These values can be selected to filter the dataset and export it to CSV or JSON formats. Currently, several techniques and chemicals are, in our opinion, unsuitable for use as anesthetics in crustaceans, and the basis for these opinions are presented. Given the evidence of a pain-like experience in crustaceans, we propose that researchers should treat crustaceans humanely, applying the principles of good handling, care, and the management of stress and pain to safeguard their welfare. [ABSTRACT FROM AUTHOR]

Introduction Offshore oil and gas (O & G) infrastructure provides hard substrata of structural complexity in marine environments and has been shown to have ecological value, particularly in oligotrophic environments. As infrastructure approaches end of life, understanding such values is critical to inform decommissioning decisions. MethodsThis study uses a decade of industry remotely operated vehicle (ROV) imagery to describe fish, invertebrate, and benthic communities on gas field infrastructure. Sampling was conducted over 22 km of flowline, three wells and one manifold in the temperate waters of Bass Strait, south east Australia in depths of 155 to 263 m.ResultsA total of 10,343 mobile animals from 69 taxa were observed. A higher diversity of fishes were observed on flowlines (28 taxa) compared to wells (19 taxa). Fish and invertebrate communities observed along flowlines were distinct from those observed on wells/manifold, however, there was also high spatial variability among the different flowlines surveyed and between the three wells and manifold. These differences appear to be driven by habitat and depth preferences of the species observed. Many sand-affiliated species were associated with buried sections of flowlines (Tasmanian giant crab Pseudocarcinus gigas, Balmain bug Ibacus peronii, slender sand burrower Creedia haswelli, red cod Pseudophycis spp., blue grenadier Macruronus novaezelandiae) whilst reef-associated and schooling species were observed on the wells/manifold (jackass morwong Nemadactylus macropterus, redbait Emmelichthys nitidus, splendid perch Callanthias australis). Species of ecological importance were also noted including the Australian fur seal (Arctocephalus pusillus doriferus), long-lived foxfish (Bodianus frenchii), and handfish (Brachionichthyidae spp).DiscussionThis study describes the habitat value of oil and gas infrastructure in a data poor temperate region that is important for understanding how the decommissioning of these structures may affect local marine ecosystems and fisheries. Therefore, it is critical to understand the habitat value of O&G infrastructure to marine life in the Bass Strait and whether decommissioning of these structures affect local marine ecosystems and fisheries. This study shows the complexity of determining temporal change in biodiversity values associated with these O & G structures from historical industry datasets that will be key for informing future decommissioning options. We also provide some guidance on how future quantitative data can be obtained in a systematic way using industry ROV data to better inform ecological investigations and decommissioning options.

A giant phyllosoma larva, assigned to the final stage, was collected from off Peru. This specimen was determined to be Projasus bahamondei George, 1976 by DNA barcoding, and morphological description was given for the first time in the genus Projasus George and Grindley, 1964. The present phyllosoma was characteristic of having very wide cephalic shield (about 2.3 times of thorax width), median rostrum, eminent setose exopods on the second and third maxillipeds, and five stout spines on basial endite of maxillule. Projasus phyllosoma has morphological characteristics of both 'Silentes' and 'Stridentes' groups in the family Palinuridae. [ABSTRACT FROM AUTHOR]

In many decapod crustaceans, escape tailflips are triggered by lateral giant (LG) and medial giant (MG) interneurons, which connect to motor giant (MoG) abdominal flexor neurons. Several decapods have lost some or all of these giant neurons, however. Because escape-related giant neurons have not been documented in palinurans, I examined tailflipping and abdominal nerve cords for giant neurons in two scyllarid lobster species, Ibacus peronii and Ibacus alticrenatus. Unlike decapods with giant neurons, Ibacus do not tailflip in response to sudden taps. Ibacus can perform non-giant tailflipping: the frequency of tailflips during swimming is adjusted by altering the gap between each individual tailflip. Abdominal nerve cord sections show no LG or MG interneurons. Backfilling nerve 3 of abdominal ganglia revealed no MoG neurons, and the fast flexor motor neuron population is otherwise identical to that described for crayfish. The loss of giant neurons in Ibacus represents an independent deletion of these cells compared to other reptantian decapods known to have lost these giant neurons. This loss is correlated with the normal posture in scyllarids, in which the last two abdominal segments are flexed, and an alternative defensive strategy, concealment by digging into sand. [Copyright &y& Elsevier]

We develop a potentially widely applicable framework for analysing the vulnerability, resilience risk and exposure of chondrichthyan species to all types of anthropogenic stressors in the marine environment. The approach combines the three components of widely applied vulnerability analysis (exposure, sensitivity and adaptability) (ESA) with three components (exposure, susceptibility and productivity) (ESP) of our adaptation of productivity–susceptibility analysis (PSA). We apply our 12‐step ESA‒ESP analysis to evaluate the vulnerability (risk of a marked reduction of the population) of each of 132 chondrichthyan species in the Exclusive Economic Zone of southern Australia. The vulnerability relates to a species' resilience to a spatial (or suitability) reduction of its habitats from exposure to up to eight climate change stressors. Vulnerability also relates to anthropogenic mortality added to natural mortality from exposure to the stressors of five types of fishing and seven other types of anthropogenic hazards. We use biological attributes as risk factors to evaluate risk related to resilience at the species or higher taxonomic level. We evaluate each species' exposure to anthropogenic stressors by assigning it to one of six ecological groups based on its lifestyle (demersal versus pelagic) and habitat, defined by bathymetric range and substrates. We evaluate vulnerability for 11 scenarios: 2000–2006 when fishing effort peaked; 2018 following a decade of fisheries management reforms; low, medium and high standard future carbon dioxide equivalent emissions scenarios; and their six possible climate–fishing combinations. Our results demonstrate the value of refugia from fishing and how climate change exacerbates the risks from fishing. [ABSTRACT FROM AUTHOR]

Achelatan lobsters, also known as spiny and slipper lobsters, develop via a highly specialised larval form. This special larva, phyllosoma, is flat, translucent, possesses elongate legs and can grow to enormous sizes. Although these larvae may appear very fragile, they are well-known as fossils. Thousands of specimens have been found in the lithographic limestone of Southern Germany (Tithonian, Upper Jurassic, about 150 mya). At least three types of fossil, but modern-appearing phyllosoma larvae are known. Additionally, fossil larvae that possess only some of the characters of modern-day phyllosoma larvae are known from the same Lagerstätte, but also from the younger limestone beds of Lebanon. Here we report a new achelatan fossil from the older Posidonia Shale (Toarcian, Lower Jurassic, 175-183 mya). The specimen shows certain characters of a phyllosoma larva, but other characters appear like those of post-phyllosoma stages of achelatan lobsters. This specimen is therefore the oldest occurrence of an achelatan lobster larva. We compare the new specimen with other fossil larvae with such mixed or "intermetamorphic" morphologies. [ABSTRACT FROM AUTHOR]

The technique of underwater acoustic localization (UAL) is widely used to track submerged targets. In the present study, we consider UAL in the specific application of locating the Mediterranean slipper lobster, Scyllarides latus (S. latus), for the aim of continuous and long-term investigation of its movement patterns. Since visual inspections only offer a snapshot to the life of these nocturnal crustaceans, we used underwater acoustic tags and deployed the first testbed to track a community of S. latus through UAL. The testbed included 19 acoustically tagged S. latus, as well as a sensor network of four receivers that record the time-of-arrival of detected tag's emissions. The testbed operated for six months, and the data collected were analyzed offline. In this paper, we describe the design details of our testbed. We discuss the considerations in choosing both the type of acoustic tags and the structure of the testbed. We also present our algorithm to time synchronize the receivers, and the localization procedure. Our preliminary results show that, for this long-term deployment, the widely used model of clock offset for the receivers is too simplified, and that time synchronization must consider also the clock's skew. We also show that the tagged lobsters are mostly detected by fewer than three receivers, thereby making localization using traditional trilateration methods highly challenging. Finally, preliminary results for the localization of the tagged lobsters in the deployment area are presented. [ABSTRACT FROM AUTHOR]

Achelatan lobsters, also known as spiny and slipper lobsters, develop via a highly specialised larval form. This special larva, phyllosoma, is flat, translucent, possesses elongate legs and can grow to enormous sizes. Although these larvae may appear very fragile, they are well-known as fossils. Thousands of specimens have been found in the lithographic limestone of Southern Germany (Tithonian, Upper Jurassic, about 150 mya). At least three types of fossil, but modern-appearing phyllosoma larvae are known. Additionally, fossil larvae that possess only some of the characters of modern-day phyllosoma larvae are known from the same Lagerstätte, but also from the younger limestone beds of Lebanon. Here we report a new achelatan fossil from the older Posidonia Shale (Toarcian, Lower Jurassic, 175-183 mya). The specimen shows certain characters of a phyllosoma larva, but other characters appear like those of post-phyllosoma stages of achelatan lobsters. This specimen is therefore the oldest occurrence of an achelatan lobster larva. We compare the new specimen with other fossil larvae with such mixed or "intermetamorphic" morphologies. [ABSTRACT FROM AUTHOR]

High-speed video recordings of escape responses in freely behaving crayfish revealed precisely coordinated movements of conspicuous head appendages, the antennal scales, during tail-flips that are produced by giant interneurons. For tail-flips that are generated by the medial giants (MG) in response to frontal attacks, the scales started to extend immediately after stimulation and extension was completed before the animal began to propel backwards. For tail-flips that are elicited by caudal stimuli and controlled by the lateral giants (LG), scale extensions began with significant delay after the tail-flip movement was initiated, and full extension of the scales coincided with full flexion of the tail. When we used implanted electrodes and stimulated the giant neurons directly, we observed the same patterns of scale extensions and corresponding timing. In addition, single action potentials of MG and LG neurons evoked with intracellular current injections in minimally restrained preparations were sufficient to activate scale extensions with similar delays as seen in freely behaving animals. Our results suggest that the giant interneurons, which have been assumed to be part of hardwired reflex circuits that lead to caudal motor outputs and stereotyped behavior, are also responsible for activating a pair of antennal scales with high temporal precision. [ABSTRACT FROM AUTHOR]

Bottom-trawl data collected by the RV Dr Fridtjof Nansen off Mozambique (in 1990, 2007 and 2018) and off eastern South Africa (in 2018) were analysed to investigate the distribution, abundance and size composition of the smooth fan lobster Ibacus novemdentatus as a potential fisheries resource. The lobsters occurred shallower (depth 53–297 m) than traditional deep-water trawl grounds, were concentrated in 'hotspots' at the seaward edges of sand/mud banks at the Thukela Bank, Delagoa Bight and Sofala Bank, and exhibited segregated juvenile and adult populations. Three other high-value lobster species and several marketable teleost species occurred in trawl nets where I. novemdentatus was present. Further exploration by trawling should be considered to better define hotspots of adults of this species and to investigate the contribution that I. novemdentatus could make to mixed-species commercial catches. [ABSTRACT FROM AUTHOR]

Many marine species are predicted to shift their ranges poleward due to rising ocean temperatures driven by climate change. For benthic marine species with pelagic larval stages, poleward range shifts are often facilitated through pelagic larval transport via western boundary currents (WBC). By surveying pelagic larval distributions within WBCs, species advected poleward of their known distributions can be identified and monitored. Palinurid and scyllarid lobster larvae (phyllosoma) have long pelagic larval durations, providing high potential for poleward advection. We surveyed spatial distribution of phyllosoma within the western-boundary East Australian Current. Due to difficulties morphologically identifying phyllosoma, we tested the utility of molecular identification using cytochrome c oxidase I (COI). From COI sequences of 56 phyllosoma and one postlarva, 65% of sequences consisted of good-quality mitochondrial DNA. Across water types sampled, scyllarid phyllosoma exhibited relatively homogeneous distribution, whereas palinurid phyllosoma exhibited heterogeneous distribution with greatest abundance inside a warm core eddy on the south coast of eastern Australia. Two tropical and one subtropical palinurid species were detected ~75–1800 km to the south or south-west of their known species distribution. Our results indicate tropical lobster species are reaching temperate regions, providing these species the opportunity to establish in temperate regions if or when environmental conditions become amenable to settlement. Many marine species are predicted to shift their ranges poleward in response to environmental changes driven by climate change. We used DNA barcoding to identify lobster larvae in south-east Australia, examining their distribution and poleward dispersal from nearest adult populations. Tropical lobster larvae reached temperate regions, providing the opportunity for settlement of these species in temperate regions under favourable environmental conditions. [ABSTRACT FROM AUTHOR]

Incremental refinements were made to a generic Nordmøre-grid to minimise bycatches of blue swimmer crabs Portunus armatus and giant cuttlefish Sepia apama, while maintaining catches of western king prawns Melicertus latisulcatus in the Spencer Gulf penaeid-trawl fishery. These refinements involved varying bar spaces, escape-exit areas and guiding-panel lengths, and were compared against a conventional trawl. Catches of teleosts and M. latisulcatus largely remained unaffected by the changes. Maximum reductions in P. armatus and S. apama bycatches (both ~90%) were achieved with a Nordmøre-grid comprising 38-mm bar spaces, 0.81- or 1.05-m2 escape exits and a 2.7-m guiding panel. Catching fewer P. armatus should reduce abrasion and crushing of M. latisulcatus in the codend and so increase the value of this targeted species. While noting some unresolved operational concerns, these results demonstrate the potential improvements in selectivity in this fishery using a Nordmøre-grid, primarily by mechanical separation. [ABSTRACT FROM AUTHOR]

The slipper lobster Scyllarides delfosi is an important resource captured by fishery fleets of red lobster (Panulirus argus westonii) in northern Brazil. Despite the economic potential of this species, information on its biological and fishery aspects is still nonexistent. This study was conducted using four-year data on slipper lobster (2001 and 2003, 2013 and 2014) to analyse population structure and estimate fecundity and egg size of S. delfosi. A total of 547 slipper lobsters, S. delfosi, were collected. Ovigerous females and individuals of all size classes were captured by the fleet, mostly individuals newly recruited to the adult stock. These lobsters showed a 7-mm decrease in total mean length over a period of 10 years. Fecundity ranged from 24,710 to 190,060 eggs and egg diameter ranged from 0.60 to 0.64 mm. Research on life cycle, reproduction, and growth of S. delfosi is essential to provide support for the sustainable exploitation of this species, which is considered by-catch on the northern Brazilian coast, and as such, has no adequate public policies regarding its management. [ABSTRACT FROM AUTHOR]