Current theory suggests that aggressive behavior in the crayfish is largely modulated and regulated by the neurotransmitter serotonin (5-HT). To test this theory that links serotonin to aggression, we performed a series of drug treatments using various serotonin-related chemicals to measure their effects on subsequent aggressive behavior. Treatments included serotonin, the serotonin precursor tryptophan

In this study, we explored the gill mRNA expression ofNa+/K+-ATPase α1 (NKAα1) and Na+/K+/2Cl− cotransporter 1a(NKCC1a) in an amphibious mudskipper species, Periophthalmus waltoniat high salinities of mangrove tidal zones. Fish were exposed to four salinities including 35 (control), 45, 55, and 70 g kg−1. The branchial transcripts of NKAα1 were elevated in fish kept at 55 and 70 g kg−1 salinities with

The nonapeptide hormone arginine vasotocin (VT) regulates osmotic balance in fishes by modulating ion and water transport. While VT’s osmoregulatory effects arise in part via changes in VT secretion, it remains uncertain which nonapeptide receptors mediate these effects, or whether adjustments in VT degradation also contribute. This study characterized gene transcript profiles for all known teleost

We tested the orientation capabilities during jumping in blackspotted rockskippers (Entomacrodus striatus). Amphibious fish routinely navigate between terrestrial and aquatic habitats and use either spatial mapping or visual cues to determine where to safely jump. We recorded jumping direction during three experiments: training, visual cue disruption, and spatial memory disruption. During the first

The nonapeptide hormone arginine vasotocin (VT) regulates osmotic balance in fishes by modulating ion and water transport. While VT’s osmoregulatory effects arise in part via changes in VT secretion, it remains uncertain which nonapeptide receptors mediate these effects, or whether adjustments in VT degradation also contribute. This study characterized gene transcript profiles for all known teleost

Mahi-mahi (Coryphaena hippurus) are photopic predators that rely on vision for predator avoidance and foraging behavior. Research conducted on Mahi-mahi vision has been primarily focused on adults, with limited knowledge of the visual function and eye development in early life-stages. In this study, larval Mahi-mahi were obtained from spawning wild-caught broodstock and exposed to an optomotor response

Sustainable aquaculture of the green guapote Mayaheros beani requires better understanding their physiology and composition. In that context, this research focused on the study of hematology, proximal and fatty acid (FA) composition of wild and farmed green guapote. Results showed no significant differences between wild and farmed fish in red blood cell count (1.77-2.57 ×106 cel µL-1), hemoglobin (11

Amphibians are increasingly challenged with salinization due to factors such as elevated sea level associated with climate change, the use of road salts, and lowering of water tables. Aldosterone is a steroid hormone that is produced by the adrenal cortex and is involved in osmotic regulation and may play an important role in amphibian acclimation to elevated salinity. We studied the effects of salinity

Procambarus clarkii  is a freshwater crayfish native to the southern central United States and northern Mexico. In Brazil, it is only present in natural environment in the state of São Paulo. Nutritional and reproductive markers were quantified and characterized, as well as intermediate metabolism and oxidative balance in females of P. clarkii collected in a natural environment over a seasonal cycle

The use of animal-borne imaging and environmental data collection systems (AVEDs) can provide behavioral and ecological information of animals that many other technologies cannot usually offer. However, many previous AVEDs have been designed for larger sharks, and there is a need for a technology that permits the collection of behavioral and ecological data for small sharks. In this study, we developed

Sustainable aquaculture of the green guapote Mayaheros beani requires better understanding their physiology and composition. In that context, this research focused on the study of hematology, proximal and fatty acid (FA) composition of wild and farmed green guapote. Results showed no significant differences between wild and farmed fish in red blood cell count (1.77-2.57 ×106 cel µL-1), hemoglobin (11

Amphibians are increasingly challenged with salinization due to factors such as elevated sea level associated with climate change, the use of road salts, and lowering of water tables. Aldosterone is a steroid hormone that is produced by the adrenal cortex and is involved in osmotic regulation and may play an important role in amphibian acclimation to elevated salinity. We studied the effects of salinity

In this study, we evaluated the behavioural characteristics of the epithelial tissues of sea cucumber (Apostichopus japonicus) subjected to illumination. The behavioural results indicated that the tentacles, tube feet, and spines were sensitive to light with structural changes. Among the three epithelial tissues, the tentacles were the most sensitive with the shortest reaction and recovery times, whereas

The immune response is a complex network composed of various molecules, cells and signaling pathways in crustacean. Cadmium-induced immunosuppression has been widely researched, but its underlying mechanism on crayfish proPO remains to be elucidated. In this study, the relationship between proPO activity in haemolymph and the activation of p38MAPK and Nrf2 in hepatopancreas was evaluated after red

Fiddler crabs are numerically dominant consumers within salt marshes and understanding how their behavior is influenced by human activities can therefore shed light on the health of disturbed marsh communities. We investigated how various levels of human influence in South Carolina salt marshes alter male waving behavior in the sand fiddler crab Leptuca pugilator across 21 marsh sites. We show that

Fish odor induces predator avoidance behaviors in zooplankton, like vertical migration, by making zooplankton more responsive to light. Odor cues that alter behavior in marine crustacean zooplankton in the laboratory include sulfated glycosaminoglycans (sGAGs) derived from fish body mucus. Few studies quantify these cues in estuarine/marine environments or assess whether laboratory studies reflect

The implementation of spatial protection measures is currently a priority in batoid species' conservation strategies, but their spatial ecology remains largely unknown. We provide some preliminary insights into the movement patterns of the white skate (Rostroraja alba), a batoid classified as Critically Endangered in European waters. Three individuals (two females: one mature, one immature; and one

This paper examines the responses of the fluted giant clam Tridacna squamosa pediveligers to elevated temperature and reduced light levels. In a light reduction experiment, a total of 104,000 T. squamosa pediveligers were exposed to four different levels of shading for approximately one month. The most heavily shaded treatment, at 0.4% of ambient light, had significantly lower survival than the other

The daily rhythm of PERIOD protein (PER) expression is an integral component of the circadian clock, which is found among a broad range of animal species including fruit flies, marine mollusks and even humans. The use of antibodies directed against PER has provided a helpful tool in the discovery of PER homologues and the labeling of putative pacemaker cells, especially in animals for which an annotated

Minuca mordax is a model for studies on ocean acidification and sea-level rise because lives in mangroves and riverbanks with low pH. We investigated the physiology of the crabs exposed to differents pH (6.5 and 5.8) and salinity (25, 30, 35, 40 45S). There was not mortality or alterations in the hypo-osmoregulation, suggesting that the factors did not affect salt absorption/secretion. Reduced pH changed

This study detailed the histomorphology of the male reproductive system and seasonality in the reproduction of a recently described genus and species of freshwater crab Arcithelphusa cochleariformis. Results indicated that the testis and vas deferens underwent correlative changes in accord with the active, inactive and revival phases of spermatogenesis. The spermatogenic activity was at its peak during

The majority of humpback whales (Megaptera novaeangliae) undertake an annual migration from high latitude feeding grounds to tropical/subtropical breeding grounds. Suitable calving habitat for this species includes warm (typically 19°C to 28°C), shallow, sheltered waters in tropical and subtropical waters. Here, we investigated occurrence of calving beyond the primary recognised breeding grounds (16°

This study investigated the effects of nonylphenol (NP) on hematological and immunological parameters in both male and female rainbow trout (Oncorhynchus mykiss). Fish were randomly distributed into six groups and administered with NP (10, 50 and 100 μg g-1 week-1 BW) and a single dose of 17-β estradiol (E2; 2 μg g-1 week-1 BW, positive control). The solvent controls received ethanol and coconut oil

The objective of this study was to characterize the digestive proteases of totoaba (Totoaba macdonaldi). Fish were sacrificed to obtain the multienzymatic extracts from the stomach and intestine, and determine the stability and optimum pH and temperature values. Residual activity and number of isoforms were determined with some inhibitors. Optimal pH of stomach proteases was 2, with stability above

The white-clawed crayfish (Austropotamobius pallipes), is classified as endangered in the 2010 IUCN Red List and is protected under Irish and European legislation due to a drastic decline in abundance and range over the past century. Mark-recapture methods play a vital role in the process of estimating population size, and in the monitoring and conservation of mobile species. A variety of marking techniques

Ecological light pollution (ELP) is quickly becoming a worldwide concern and can negatively affect aquatic ecosystems. The given intensity and spectrum of a light source can influence how organisms function within their environment. These properties of artificial lighting at night (ALAN) and their impacts on the physiology and behaviour of crayfish were examined in this work. Hemolymph was obtained

There is increasing evidence showing that the gasotransmitter hydrogen sulfide (H2S) and NF-κB-mediated signaling may play an important role in regulating immune response. However, essentially nothing is known about them in crustaceans, especially the red swamp crayfish (Procambarus clarkii). In this work, we used immunohistochemical method to investigate, for the first time, the presence and distribution

To evaluate the involvement of plasma cortisol in sex determination in hermaphrodite protandrous sex-changing fish, sexually immature false clown anemonefish (Amphiprion ocellaris) were kept in groups of 3 individuals for 360 days. Observations of time-course changes of diurnal behaviour and plasma concentrations of cortisol, oestradiol, and 11-ketotestosterone were evaluated. The social hierarchy

Many critical cellular processes, including cell proliferation and tissue repair, exhibit melatonin sensitivity. We examined the effects of exogenous melatonin, photoperiod and temperature on regeneration in Phagocata gracilis, a common North American turbellarian. Planarian regeneration involves the proliferation and migration of pluripotent stem cells capable of replacing missing body components

Poor swimming performance and low hypoxia tolerance have been suggested as the main reasons for the dramatic decrease in the wild population of Chinese sucker. The present study aimed to investigate the potential for exercise training to enhance swimming performance and hypoxia tolerance in this fish species targeted for stocking enhancement. Fish were exercise trained (force to swim against a flow)

Gulf of Mannar (GoM) in the southeast coast of India is known for its coral reefs and reef-associated biodiversity. Corals in GoM were affected to a significant extent by climate change-driven coral bleaching in 2016, and are currently recovering. After the bleaching mortality that corals suffered, the competition for space between corals and sponges is obvious in GoM. Rhabdastrella globostellata is

Zebrafish, Danio rerio, is one of the most studied vertebrate models. However, there are still many aspects of its reproductive behavior to be elucidated. The aim of this work was to clarify whether males and females of this species display different behaviors according to sexual status, and the kind of cues they were exposed to (visual and/or chemical). Females in two different sexual status, pre-

The aim of this study was to determine: (1) salinity that maximizes arm regeneration in the starfish Luidia clathrata; and (2) if low food consumption or low salinity is the cause of the reduced rate of arm regeneration seen at low salinities.. An estimated salinity of 33 g kg−1 produced maximum regeneration of two arms in L. clathrata. This salinity is typically greater than that found in bays that

Like mono-species fish groups, formation of mixed-species assemblages is likely driven by trophic influences and interspecific behavioural traits. Our aim was to identify how sympatric estuarine species of differing phenotypes form mixed-species group associations, and to identify changes to group structure of fish that migrate between mono- and mixed-species groups. We used sympatric yellow-eyed mullet

The frequency and strength of extreme events are increasing due to climate change. These events have the potential to cause mass mortalities and recruitment failure in very short time scales. Here, we explored three relevant basic questions using green abalone: how the lethal levels of environmental variables (i.e. temperature, oxygen, and pH) change trough time, what the short-term synergistic effects

Many fish schools are regarded as leaderless, where any individual can guide the direction of group motion at any given moment. We conditioned a fish school of black neon tetra (Hyphessobrycon herbertaxelrodi) to find food in aparticular location, while another group swam freely with no particular goal. Groups were composed of similar individuals in terms of body size, task knowledge and hunger level

Sharks have been facing unprecedented pressure over the last decades, and ocean acidification may represent an additional threat, particularly during their most susceptible life stages. Hence, the present study aimed to investigate the effects of ocean acidification (control pCO2 ~ 400 μatm; high pCO2 ~ 900 μatm) on the growth, swimming performance and cholinergic system of juvenile white-spotted bamboo

This study describes for the first time the early gonadal morphogenesis and raises the possibility of occurrence of protandric hermaphroditism in the Mexican snook (Centropomus poeyi). To achieve this, histological analysis of early gonadal differentiation was performed in 105 juvenile specimens ranging from 136 to 367 days post-hatching (dph). The early gonadal differentiation of the Mexican snook

One hundred and eight juvenile Acanthopagrus latus were transported from their natural habitat and kept in tanks (300 L) with 20 ppt salinity for 14 days. After 24h starvation, the fish were exposed to salinity of 34, 12, and 5 ppt; then, blood samples were taken after 0, 2, 24, and 48h after the exposure. Blood electrolytes did not show significant changes in response to variation in the environmental

The effects of cadmium concentration (0, 2.5 and 5 mg L−1) on melanocyte-stimulating hormone (MSH), melanophore index (MI), and melanophore number (MN), as well as a microscopic examination of scale melanocytes in tilapia (Oreochromis niloticus Linnaeus, 1757) was evaluated at different salinity levels (0, 5 and 15 ppt). The levels of MSH, MI, and MN were lower in Cd-exposed fish than in control fish

The primary ecotope for Platorchestia platensis is supralittoral wrack, but occasionally this species may be found living in, and feeding on, rotting driftwood as a secondary ecotope. Lower oxygen uptake rates were measured for driftwood-fed compared with wrack-fed P. platensis. The null hypothesis that the metabolic rate in P. platensis would remain unchanged after reversing the diet from driftwood

To characterize the locomotor behaviors and their relation with physiological regulation in Chinese shrimp Fenneropenaeus chinensis, animals were held at approximately 6.0 (normoxia), 4.5, and 3.0 mg L-1 dissolved oxygen (DO) for 1 day (acute) and 15 days (chronic), after which the swimming and tail-flipping abilities, and the activities of key enzymes involved in anaerobic and aerobic metabolism in

Stomatopod crustaceans have highly mobile, independently moving compound eyes that are sensitive to both linearly and circularly polarized light. They rotate their eyes to predictable angles when viewing a linearly polarized target, and they scan their eyes frequently to sample the visual field. Angles of scans are roughly perpendicular to the plane of the midband (a set of specialized parallel rows

As global temperatures rise, streams and rivers are predicted to be more severely impacted than other ecosystems, due in part to the limited mobility of aquatic invertebrates. Compared to many terrestrial animals, freshwater snails have particularly low potential for migration and thus are not expected to be able to compensate for climate warming with active dispersal. In freshwater animals, several

Rates of oxygen consumption in seawater standardized for size (mass or body length) were compared for a representative supralittoral, wrack generalist talitrid – Platorchestia platensis and a representative driftwood, specialist talitrid – Macarorchestia remyi. Oxygen consumption in seawater was significantly less in M. remyi. This confirms the view that a reduced standard metabolic rate, and consequent

(2018). Correction. Marine and Freshwater Behaviour and Physiology: Vol. 51, No. 3, pp. 213-213.

The male reproductive system of Amazon freshwater crabs Sylviocarcinus pictus and Dilocarcinus pagei were described and compared in terms of anatomy and histochemistry In addition, sperm transfer experiments of D. pagei with sequential copulations were performed and the anatomy of the seminal receptacle was checked. The anatomy of the male reproductive system of both species is an inverted ‘U’ shape

Locomotion has been a well-studied avenue for questions regarding the costs of autotomy. However, previous studies have focused on traditional means of locomotion such as walking, running, or swimming; an unexplored aspect of locomotion as it relates to the costs of autotomy is the dorso-ventral righting reflex, or DVRR. Using a comprehensive set of treatment groups, we explored how autotomy affects

(2018). ‘Solo datasets’: unexpected behavioural patterns uncovered by acoustic monitoring of single individuals. Marine and Freshwater Behaviour and Physiology: Vol. 51, No. 3, pp. 183-201.

Autotomy is the ability to shed an appendage, and arthropods can autotomize to escape predation or a fouled molting event. Myriad aspects of autotomy have been previously explored, yet quantitative data on the force needed to induce autotomy is lacking. We tested three leg types in Hemigrapsus nudus, and our results showed that hind legs require the most amount of force to autotomize (~45 N-s) compared

Swimming is of vital importance for aquatic organisms because it determines several aspects of fitness, such as encounter rates with food, predators, and mates. Generally, rotifer swimming speed is measured by manual tracking of the swimming paths filmed in videos. Recently, an open-source package has been developed that integrates different open-source software and allows direct processing and analysis

The bearded fireworm (Hermodice carunculata) is an amphinomid polychaete with a circumtropical Atlantic-Mediterranean distribution. In the Mediterranean Sea, very little information is available on its feeding habits and ecological functions. Here, its increasing abundance and the ability to actively prey on a keystone sea urchin species suggest potential repercussions for the structure and functioning

Corals exhibit different responses to increasing temperature but it remains unclear whether this is determined exclusively by symbiont type or by intrinsic properties of the host. Here, we investigated the response to elevated temperature of symbionts of the same ITS2 type from three acroporid species from Bolinao, northwestern Philippines. Maximum quantum yield (Fv/Fm) of PSII was measured in symbionts

Most studies of foraging in shell-less gastropods have focused on the ubiquitous generalist sea hares (family Aplysiidae; subfamily Aplysiinae: Aplysia spp., Dolabella spp). Here we studied movement in a specialist sea hare (the seacat, Dolabrifera dolabrifera; subfamily Dolabriferinae). Seacats in each of 7 different tidepools on Isla Naos in the Gulf of Panama emerged precisely when the daytime ebbing

The effects of meal size on the postprandial metabolic response and of digestion on the post-exercise metabolic recovery process were investigated in juvenile black carp (Mylopharyngodon piceus) . Experimental fish were forcedly fed with compound feed (meal sizes: 0.5%, 1% and 2% body weight). Then, the postprandial oxygen consumption rate and excess post-exercise oxygen consumption (EPOC) of the experimental

The present study evaluated the effects of internal illuminance and shelter shape on shelter selection by Japanese eels to enable the preservation or construction of suitable shelters for the Japanese eel. Japanese eels were able to distinguish a 1.25-fold difference in illumination inside the shelters, and preferred darker shelters. When the internal illumination of two shelters with the same shape

(2018). Editorial. Marine and Freshwater Behaviour and Physiology: Vol. 51, No. 1, pp. 1-2.

Pyrethroids, the widely used pesticides, are highly toxic to aquatic organisms. However, little information is available on their toxicity on crustaceans. We utilized imagoes of Echinogammarus tacapensis to elucidate the effects of sublethal concentrations of permethrin. The LC50 (48, 72, and 96 h) was assessed considering several pesticide concentrations (ranging between 0.5 and 100 ng L−1) using

Metabolic rates provide an estimate of the cost of living for different organisms that can readily be compared across species to provide an estimate of their relative requirements for survival. As such, metabolic rates have been measured for decades on a wide range of organisms. Here, we review published estimates of metabolic rates for brachyuran crabs, a ubiquitous and ecologically and economically

Corallivore animals play vital role in coral reef ecology. Predation on corals by other organisms has not been studied properly in the Indian waters. This study reports the first observation of predation by cushion star (Culcita schmideliana) on coral polyps in Gulf of Mannar (GoM), southeast India. During our regular underwater surveys in GoM, C. schmideliana was found preying on hard coral Acropora