Dietary Protein Affects the Growth Response and Tissue Composition of Juvenile Slipper Lobster ().

The effect of different dietary protein levels on apparent feed intake, apparent digestibility, body composition, nutrient retention, and growth efficiency of juvenile slipper lobster () were evaluated for 74 days. Three isoenergetic and isolipidic feeds were formulated with crude protein levels of 445, 490, and 551 g kg DM, designated as P45, P50, and P55, respectively. Lobsters were fed one of these feeds in quadruplicate tanks, with eight lobsters (mean initial wet weight 6.

Essentiality of dietary cholesterol and its interactions with phospholipid in juvenile slipper lobster (Thenus australiensis).

This study was conducted to verify the essentiality of dietary cholesterol for early juvenile slipper lobster, Thenus australiensis (initial weight 4.50 ± 0.72 g, mean ± SD, CV = 0.

Ontogeny of the Cytochrome P450 Superfamily in the Ornate Spiny Lobster ().

Cytochrome P450s (CYP450s) are a versatile superfamily of enzymes known to undergo rapid evolution. They have important roles across growth and development pathways in crustaceans, although it is difficult to characterise orthologs between species due to their sequence diversity. Conserved CYP450s enzymes in crustaceans are those associated with ecdysteroidogenesis: synthesising and breaking down the active moult hormone, 20-hydroxyecdysone.

Application of a stoichiometric bioenergetic approach and whole-body protein synthesis to the nutritional assessment of juvenile Thenus australiensis.

The present study successfully combined a stoichiometric bioenergetic approach with an endpoint stochastic model to simultaneously determine specific dynamic action, metabolic substrate use and whole-body protein synthesis in juvenile slipper lobster Thenus australiensis. Juvenile lobsters were fasted for 48 h to investigate routine metabolism before receiving a single meal of formulated feed containing 1% N-labeled Spirulina. Postprandial oxygen consumption rate, dissolved inorganic carbon, and total nitrogen excretion returned to the pre-feeding level within 24 h.

Tropical rock lobster (Panulirus ornatus) uses chemoreception via the antennular lateral flagellum to identify conspecific ecdysis.

The tropical rock lobster, Panulirus ornatus, is a commercially important aquaculture species exhibiting complex social interactions in laboratory culture, including cannibalism of moulting conspecifics. Cannibalism of soft-shelled post-moult stage individuals is a major limitation during the juvenile stage of culture. Not limited to P.

Examining the inorganic elemental composition of lobster phyllosoma (Panulirus ornatus) with X-ray fluorescence microscopy.

The ornate spiny rock lobster, Panulirus ornatus, is an attractive candidate for aquaculture. The larval stages of spiny lobsters, known as phyllosoma, are complex with many developmental stages. Very little is known about the inorganic element composition of phyllosoma.

Development of a two-current choice flume behavioural bioassay for juvenile Panulirus ornatus response to moulting cues.

Characterising crustacean behaviour in response to conspecific chemical cues contributes to our evolving knowledge of the drivers of their social behaviour. There is particular interest in understanding the chemical and behavioural mechanisms contributing to cannibalism at ecdysis, as this behaviour substantially limits culture productivity of several commercially important crustaceans. Before investigating the role of chemoreception in cannibalism of moulting crustaceans, we must investigate its role in detecting moulting conspecifics.

Unravelling the neuropeptidome of the ornate spiny lobster Panulirus ornatus: A focus on peptide hormones and their processing enzymes expressed in the reproductive tissues.

Neuropeptides are commonly produced in the neural tissues yet can have effects on far-reaching targets, with varied biological responses. We describe here the neuropeptidome of the ornate spiny lobster, Panulirus ornatus, a species of emerging importance to closed-system aquaculture, with a focus on peptide hormones produced by the reproductive tissues. Transcripts for a precursor to one neuropeptide, adipokinetic hormone/corazonin-related peptide (ACP) were identified in high numbers in the sperm duct of adult spiny lobsters suggesting a role for ACP in the reproduction of this species.

A Tale of Two Lobsters-Transcriptomic Analysis Reveals a Potential Gap in the RNA Interference Pathway in the Tropical Rock Lobster .

RNA interference (RNAi) has been widely utilised in many invertebrate models since its discovery, and in a majority of instances presents as a highly efficient and potent gene silencing mechanism. This is emphasized in crustaceans with almost all taxa having the capacity to trigger effective silencing, with a notable exception in the spiny lobsters where repeated attempts at dsRNA induced RNAi have demonstrated extremely ineffective gene knockdown. A comparison of the core RNAi machinery in transcriptomic data from spiny lobsters () and the closely related slipper lobsters ( where silencing is highly effective) revealed that both lobsters possess all proteins involved in the small interfering and microRNA pathways, and that there was little difference at both the sequence and domain architecture level.

The Effect of Feed Frequency on Growth, Survival and Behaviour of Juvenile Spiny Lobster ().

Spiny lobsters have a range of complex chemical communication pathways that contribute to feeding behaviour. Feed intake is modulated by feed availability and feed characteristics, such as attractiveness and palatability, with behavioural factors, such as social competition and circadian rhythm, providing an extra layer of complexity. In this study, we investigated the effect of feed frequency on survival and growth of early-stage (instar 2-6) juvenile .

The impact of seismic survey exposure on the righting reflex and moult cycle of Southern Rock Lobster (Jasus edwardsii) puerulus larvae and juveniles.

Anthropogenic aquatic noise is recognised as an environmental pollutant with the potential to negatively affect marine organisms. Seismic surveys, used to explore subseafloor oil reserves, are a common source of aquatic noise that have garnered attention due to their intense low frequency inputs and their frequent spatial overlap with coastal fisheries. Commercially important Southern Rock Lobster (Jasus edwardsii) adults have previously shown sensitivity to signals from a single seismic air gun.

Metabolic plasticity improves lobster's resilience to ocean warming but not to climate-driven novel species interactions.

Marine species not only suffer from direct effects of warming oceans but also indirectly via the emergence of novel species interactions. While metabolic adjustments can be crucial to improve resilience to warming, it is largely unknown if this improves performance relative to novel competitors. We aimed to identify if spiny lobsters-inhabiting a global warming and species re-distribution hotspot-align their metabolic performance to improve resilience to both warming and novel species interactions.

Protein sources influence both apparent digestibility and gastrointestinal evacuation rate in juvenile slipper lobster (Thenus australiensis).

Apparent digestibility and gastrointestinal evacuation rate were measured to assess the potential of five commercially available protein sources for their inclusion in feeds for juvenile slipper lobster, Thenus australiensis. Protein sources tested were fishmeal, krill meal, lupin meal, soybean meal and squid by-product meal. Apparent digestibility of crude protein ranged from 79.

Effect of dietary protein on energy metabolism including protein synthesis in the spiny lobster Sagmariasus verreauxi.

This is the first study in an aquatic ectotherm to combine a stoichiometric bioenergetic approach with an endpoint stochastic model to explore dietary macronutrient content. The combination of measuring respiratory gas (O and CO) exchange, nitrogenous (ammonia and urea) excretion, specific dynamic action (SDA), metabolic energy substrate use, and whole-body protein synthesis in spiny lobster, Sagmariasus verreauxi, was examined in relation to dietary protein. Three isoenergetic feeds were formulated with varying crude protein: 40%, 50% and 60%, corresponding to CP, CP and CP treatments, respectively.

The Chinese mitten crab genome provides insights into adaptive plasticity and developmental regulation.

The infraorder Brachyura (true or short-tailed crabs) represents a successful group of marine invertebrates yet with limited genomic resources. Here we report a chromosome-anchored reference genome and transcriptomes of the Chinese mitten crab Eriocheir sinensis, a catadromous crab and invasive species with wide environmental tolerance, strong osmoregulatory capacity and high fertility. We show the expansion of specific gene families in the crab, including F-ATPase, which enhances our knowledge on the adaptive plasticity of this successful invasive species.

Mismatch of thermal optima between performance measures, life stages and species of spiny lobster.

In an ocean warming hotspot off south-east Australia, many species have expanded their ranges polewards, including the eastern rock lobster, Sagmariasus verreauxi. This species is likely extending its range via larval advection into Tasmanian coastal waters, which are occupied by the more commercially important southern rock lobster, Jasus edwardsii. Here, thermal tolerances of these lobster species at two life stages were investigated to assess how they may respond to warming ocean temperatures.

Lobsters with pre-existing damage to their mechanosensory statocyst organs do not incur further damage from exposure to seismic air gun signals.

Staotcysts, the mechanosensory organs common to many marine invertebrates, have shown sensitivity to aquatic noise. Previously, rock lobsters (Jasus edwardsii) from a remote site with little exposure to anthropogenic noise incurred persistent damage to the statocyst and righting reflex following exposure to seismic air gun signals. Here, J.

Multi-Tissue Transcriptome Analysis Identifies Key Sexual Development-Related Genes of the Ornate Spiny Lobster ().

Sexual development involves the successive and overlapping processes of sex determination, sexual differentiation, and ultimately sexual maturation, enabling animals to reproduce. This provides a mechanism for enriched genetic variation which enables populations to withstand ever-changing environments, selecting for adapted individuals and driving speciation. The molecular mechanisms of sexual development display a bewildering diversity, even in closely related taxa.

Double-Stranded RNA Binding Proteins in Serum Contribute to Systemic RNAi Across Phyla-Towards Finding the Missing Link in Achelata.

RNA interference (RNAi) has become a widely utilized method for studying gene function, yet despite this many of the mechanisms surrounding RNAi remain elusive. The core RNAi machinery is relatively well understood, however many of the systemic mechanisms, particularly double-stranded RNA (dsRNA) transport, are not. Here, we demonstrate that dsRNA binding proteins in the serum contribute to systemic RNAi and may be the limiting factor in RNAi capacity for species such as spiny lobsters, where gene silencing is not functional.

CrustyBase: an interactive online database for crustacean transcriptomes.

Transcriptome sequencing has opened the field of genomics to a wide variety of researchers, owing to its efficiency, applicability across species and ability to quantify gene expression. The resulting datasets are a rich source of information that can be mined for many years into the future, with each dataset providing a unique angle on a specific context in biology. Maintaining accessibility to this accumulation of data presents quite a challenge for researchers.

Physiological status and nutritional condition of cultured juvenile Thenus australiensis over the moult cycle.

The moult cycle is arguably the most critical aspect of crustacean biology and is associated with dramatic changes in behaviour, physiology and condition. Here we describe the first detailed investigation of the combined changes in morphology, physiological status and nutritional condition over the moult cycle of juvenile T. australiensis.

Temperature alters the physiological response of spiny lobsters under predation risk.

Predation risk can strongly shape prey ecological traits, with specific anti-predator responses displayed to reduce encounters with predators. Key environmental drivers, such as temperature, can profoundly modulate prey energetic costs in ectotherms, although we currently lack knowledge of how both temperature and predation risk can challenge prey physiology and ecology. Such uncertainties in predator-prey interactions are particularly relevant for marine regions experiencing rapid environmental changes due to climate change.

Physiological mechanisms linking cold acclimation and the poleward distribution limit of a range-extending marine fish.

Extensions of species' geographical distributions, or range extensions, are among the primary ecological responses to climate change in the oceans. Considerable variation across the rates at which species' ranges change with temperature hinders our ability to forecast range extensions based on climate data alone. To better manage the consequences of ongoing and future range extensions for global marine biodiversity, more information is needed on the biological mechanisms that link temperatures to range limits.

Neural remodelling in spiny lobster larvae is characterized by broad neuropeptide suppression.

Neuropeptides are ancient endocrine components which have evolved to regulate many aspects of biology across the animal kingdom including behaviour, development and metabolism. To supplement current knowledge, we have utilized a transcriptome series describing larval development in the ornate spiny lobster, Panulirus ornatus. The biology of this animal has been leveraged to provide insights into the roles of molting, metamorphosis and metabolism across the neuropeptide family.