Estuarine Crab Research Articles

Phenotypic flexibility in response to environmental salinity in the euryhaline crab Neohelice granulata from the mudflat and the saltmarsh of a SW coastal lagoon

This study constitutes a first attempt to investigate intraspecific differences in osmoregulatory capacity and digestive and metabolic responses at the biochemical level in relation to hyper- and hypo-regulation in a single species of estuarine crab inhabiting contrasting habitats within a same intertidal area. We compared hemolymph osmolality, key digestive enzymes, glycemia and energy reserves in Neohelice granulata (Dana in Proc Acad Nat Sci Philadelphia 5:247–254, 1851) from the mudflat and saltmarsh of Mar Chiquita coastal lagoon (37°32′/37°45′S-57°19′/57°26′W) under a wide range of salinities (6–60 psu). Individuals from both sites exhibited high and similar osmoregulatory capacity, but while in individuals from mudflat low and high salinities affected lipase activity in hepatopancreas and triglycerides in muscle, in crabs from saltmarsh, high salinities affected glycogen in anterior gills. Low salinity differentially affected free glucose in anterior gills. The results suggest the occurrence of intraspecific distinct digestive and metabolic adjustments in relation to osmoregulatory responses and habitat.

Reproductive characteristics of two estuarine crabs Chasmagnathus convexus and Helice tridens (Brachyura: Varunidae) in the Shigenobu River Estuary, Japan

Reproductive characteristics of two estuarine crabs Chasmagnathus convexus and Helice tridens (Brachyura: Varunidae) in the Shigenobu River Estuary, Japan

Turbine Sound May Influence the Metamorphosis Behaviour of Estuarine Crab Megalopae

It is now widely accepted that a shift towards renewable energy production is needed in order to avoid further anthropogenically induced climate change. The ocean provides a largely untapped source of renewable energy. As a result, harvesting electrical power from the wind and tides has sparked immense government and commercial interest but with relatively little detailed understanding of the potential environmental impacts. This study investigated how the sound emitted from an underwater tidal turbine and an offshore wind turbine would influence the settlement and metamorphosis of the pelagic larvae of estuarine brachyuran crabs which are ubiquitous in most coastal habitats. In a laboratory experiment the median time to metamorphosis (TTM) for the megalopae of the crabs Austrohelice crassa and Hemigrapsus crenulatus was significantly increased by at least 18 h when exposed to either tidal turbine or sea-based wind turbine sound, compared to silent control treatments. Contrastingly, when either species were subjected to natural habitat sound, observed median TTM decreased by approximately 21–31% compared to silent control treatments, 38–47% compared to tidal turbine sound treatments, and 46–60% compared to wind turbine sound treatments. A lack of difference in median TTM in A. crassa between two different source levels of tidal turbine sound suggests the frequency composition of turbine sound is more relevant in explaining such responses rather than sound intensity. These results show that estuarine mudflat sound mediates natural metamorphosis behaviour in two common species of estuarine crabs, and that exposure to continuous turbine sound interferes with this natural process. These results raise concerns about the potential ecological impacts of sound generated by renewable energy generation systems placed in the nearshore environment.

Biochemical responses and physiological status in the crab Hemigrapsus crenulatus (Crustacea, Varunidae) from high anthropogenically-impacted estuary (Lenga, south-central Chile)

Estuarine environmental assessment by sub-individual responses is important in order to understand contaminant effects and to find suitable estuarine biomonitor species. Our study aimed to analyze oxidative stress responses, including glutathione-S-transferase (GST) activity, total antioxidant capacity (ACAP) and lipid peroxidation levels (TBARS) in estuarine crabs Hemigrapsus crenulatus from a high anthropogenically-impacted estuary (Lenga) compared to low and non-polluted estuaries (Tubul and Raqui), in a seasonal scale (winter–summer), tissue specific (hepatopancreas and gills) and sex related responses. Results showed that hepatopancreas in male crabs better reflected inter-estuary differences. Morpho-condition traits as Cephalothorax hepatopancreas index (CHI) could be used as an indicator of physiological status of estuarine crabs. Discriminant analysis also showed that GST and TBARS levels in summer are more suitable endpoints for establishing differences between polluted and non-polluted sites. These results suggest the importance of seasonality, target tissue, sex and physiological status of brachyuran crabs for estuarine biomonitoring assessment.

Horizontal distribution of megalopae of Brachyura (Crustacea, Decapoda) in a South American tropical estuary

The available information on the larval phase of estuarine crabs in tropical habitats is scarce, despite its importance for the population dynamics of these crustaceans. The goal of the present study was to evaluate patterns of spatial distribution of megalopae along a gradient in the Ubatumirim River estuary, Ubatuba region, state of São Paulo, Brazil. Samples were taken periodically during neap and spring tides in April and November 2005. The megalopae were collected on passive collectors made from an organic substrate, at 10 sampling sites equally spaced along the two river channels of the Ubatumirim estuary. At the laboratory, larvae were identified according to available literature. Sesarmid and ocypodid crabs predominated in the samples. Megalopae settled differently in neap- and spring-tide periods, with a tendency toward increased settlement during high-amplitude tides. The highest density of megalopae was recorded at the sites near the river mouth. The observed horizontal distribution pattern probably results from the influence of seawater or from mechanisms to avoid predation and/or competition for resources. Despite problems in identifying taxa to species level, the results of the present study contribute to increase knowledge about overall trends in the horizontal distribution of megalopae in estuarine systems.

Copper effects on key metabolic enzymes and mitochondrial membrane potential in gills of the estuarine crab Neohelice granulata at different salinities

The estuarine crab Neohelice granulata was exposed (96h) to a sublethal copper concentration under two different physiological conditions (hyperosmoregulating crabs: 2ppt salinity, 1mg Cu/L; isosmotic crabs: 30ppt salinity, 5mg Cu/L). After exposure, gills (anterior and posterior) were dissected and activities of enzymes involved in glycolysis (hexokinase, phosphofructokinase, pyruvate kinase, lactate dehydrogenase), Krebs cycle (citrate synthase), and mitochondrial electron transport chain (cytochrome c oxidase) were analyzed. Membrane potential of mitochondria isolated from anterior and posterior gill cells was also evaluated. In anterior gills of crabs acclimated to 2ppt salinity, copper exposure inhibited hexokinase, phosphofructokinase, pyruvate kinase, and citrate synthase activity, increased lactate dehydrogenase activity, and reduced the mitochondrial membrane potential. In posterior gills, copper inhibited hexokinase and pyruvate kinase activity, and increased citrate synthase activity. In anterior gills of crabs acclimated to 30ppt salinity, copper exposure inhibited phosphofructokinase and citrate synthase activity, and increased hexokinase activity. In posterior gills, copper inhibited phosphofructokinase and pyruvate kinase activity, and increased hexokinase and lactate dehydrogenase activity. Copper did not affect cytochrome c oxidase activity in either anterior or posterior gills of crabs acclimated to 2 and 30ppt salinity. These findings indicate that exposure to a sublethal copper concentration affects the activity of enzymes involved in glycolysis and Krebs cycle, especially in anterior (respiratory) gills of hyperosmoregulating crabs. Changes observed indicate a switch from aerobic to anaerobic metabolism, characterizing a situation of functional hypoxia. In this case, reduced mitochondrial membrane potential would suggest a decrease in ATP production. Although gills of isosmotic crabs were also affected by copper exposure, changes observed suggest no impact in the overall tissue ATP production. Also, findings suggest that copper exposure would stimulate the pentose phosphate pathway to support the antioxidant system requirements. Although N. granulata is very tolerant to copper, acute exposure to this metal can disrupt the energy balance by affecting biochemical systems involved in carbohydrate metabolism.

Population Structure of the SW Atlantic Estuarine Crab Neohelice granulata Throughout Its Range: a Genetic and Morphometric Study

Phylogeographic patterns of the SW Atlantic estuarine crab Neohelice granulata were examined using mitochondrial DNA cytochrome oxidase I sequences and analyzed together with morphometric data. Specimens were sampled during a 4-year period (2001–2004) from 11 localities encompassing the full distributional range of this species along the SW Atlantic (22°57′ S to 42°25′ S). DNA sequences were obtained from 69 individuals belonging to seven localities, and morphometric variation in 12 continuous characters was analyzed for 646 crabs from ten localities. Strong genetic differentiation, consistent with a pattern of isolation-by-distance, was detected among all localities indicating that gene flow occurs mainly between neighboring populations. Analyses of molecular variance showed genetic subdivision between the southern (Argentina) and the northern (Brazil) sites, suggesting restricted gene flow at a regional scale. The genetic structure of this species could be divided into two distinct groups due to a limited gene flow between southern and northern regions as a consequence of larval dispersal patterns. Coastal currents in the vicinity of the Rio de la Plata likely act as a barrier to dispersal within the species range. Moreover, genetic data indicate that populations of N. granulata might have undergone a northward demographic expansion since the late Pleistocene. The morphometric analysis showed no geographical pattern of morphological differentiation, although there were differences among sampling sites.

Thermal tolerance of the crab Pachygrapsus marmoratus: intraspecific differences at a physiological (CTMax) and molecular level (Hsp70)

Temperature is one of the most important variables influencing organisms, especially in the intertidal zone. This work aimed to test physiological and molecular intraspecific differences in thermal tolerance of the crab Pachygrapsus marmoratus (Fabricius, 1787). The comparisons made focused on sex, size, and habitat (estuary and coast) differences. The physiological parameter was upper thermal limit, tested via the critical thermal maximum (CTMax) and the molecular parameter was total heat shock protein 70 (Hsp70 and Hsp70 plus Hsc70) production, quantified via an enzyme-linked imunosorbent assay. Results showed that CTMax values and Hsp70 production are higher in females probably due to different microhabitat use and potentially due to different hormonal regulation in males and females. Among females, non-reproducing ones showed a higher CTMax value, but no differences were found in Hsp70, even though reproducing females showed higher variability in Hsp70 amounts. As reproduction takes up a lot of energy, its allocation for other activities, including stress responses, is lower. Juveniles also showed higher CTMax and Hsp70 expression because they occur in greater shore heights and ageing leads to alterations in protein synthesis. Comparing estuarine and coastal crabs, no differences were found in CTMax but coastal crabs produce more Hsp70 than estuarine crabs because they occur in drier and hotter areas than estuarine ones, which occur in moister environments. This work shows the importance of addressing intraspecific differences in the stress response at different organizational levels. This study shows that these differences are key factors in stress research, climate research, and environmental monitoring.

The claw closer muscle of two estuarine crab species,Cyrtograpsus angulatusandNeohelice granulata(Grapsoidea, Varunidae): histochemical fibre type composition

Longo, M.V. and Díaz, A.O. (2011). The claw closer muscle of two estuarine crab species, Cyrtograpsus angulatus and Neohelice granulata (Grapsoidea, Varunidae): histochemical fibre type composition. —Acta Zoologica (Stockholm) 00: 1–7. This study permitted the characterization of four types of muscle fibres in the claw closer muscles of Cyrtograpsus angulatus and Neohelice granulata. Succinic dehydrogenase (SDH) for mitochondria, periodic acid Schiff (PAS) for glycogen, Sudan Black B for lipids and myosin-adenosine triphosphatase (m-ATPase) preincubated at alkaline and acid pHs were used for that purpose. The mean fibre diameters, the relative areas and frequencies of each muscle fibre type were calculated. Types I and IV would be considered ‘extreme’ groups with type I fibres large, weak and acid/alkaline-labile m-ATPase, weak SDH, PAS and Sudan, and type IV fibres small, very strong and acid/alkaline-resistant m-ATPase, strong SDH and PAS, and moderate Sudan. Types II and III would belong to a predominant ‘intermediate’ group. Type IV fibres were scarce in C. angulatus but represented 25% of the total fibre population in N. granulata. In C. angulatus, the relative area occupied by type I fibres was bigger than its relative proportion, whereas in N. granulata, types I and II had similar patterns. Concluding, variations in fibre type composition in the claw closer muscles of C. angulatus and N. granulata would be linked to different habitats and feeding behaviours.

Differences in Refuge use are Related to Predation Risk in Estuarine Crabs

ABSTRACT We determined the dominance hierarchy in competition for refuges by the xanthid crabs Panopeus simpsoni, Eurypanopeus depressus, Rhithropanopeus harrisii, and juvenile Callinectes sapidus, and used it to predict predation risk from adult blue crabs in laboratory experiments at two salinities. Experiments were first run with pairwise combinations of species with limited refuges. To determine any effects of diffuse competition on dominance and predation risk, all four species were then held together with limited refuges. The same process was then repeated in experiments with a blue crab predator, again with limited refuges. Juvenile C. sapidus and E. depressus were dominant over P. simpsoni and R. harrisii in occupying shelters at both salinities, in both paired- and multiple-species combinations. Dominance in refuge use increased with salinity in C. sapidus, E. depressus, and P. simpsoni, but not in R. harrisii. Because they were more dominant, C. sapidus and E. depressus sustained lower mortality...

Morphological and Molecular Comparison of Hemigrapsus crenulatus (Milne Edwards, 1837) (Brachyura: Varunidae) from New Zealand and Chile: Was Miss Rathbun Right?

Abstract The estuarine crab Hemigrapsus crenulatus (H. Milne Edwards, 1837) is a native of New Zealand, but it is also known from the coast of Chile some 8900 km eastwards across the Pacific. Mary Rathbun (1898) was the first person to call crabs from the Chilean coast, H. crenulatus, saying that they were conspecific with crabs described by Milne Edwards (1837). However, Bennett (1964) took the advice of H. Balss that the Chilean species should be known as Hemigrapsus granarius (Nicolet, 1849). No type specimens are available for either of these species. We have used mitochondrial 16S rRNA and COI sequences derived from fresh specimens to find out who was correct. There are few if any consistent morphological differences between populations from either side of the South Pacific and very few molecular differences (only 3 fixed nucleotide differences out of 1190 bp total sequenced – 0.25%). None of these differences exceed variation within either population, so we must declare Miss Rathbun the winner! The ...

Effects of parathion on cardiac rate, ventilatory frequency and hemolymphatic gas levels in the estuarine crab Neohelice granulata (Decapoda, Brachyura)

Adult crabs Neohelice granulata were exposed for 96 h to 0.125 mg/L of parathion under complete submersion. Crabs were then exposed to air for 6 h (emersion period) to be finally re-submerged. Cardiac rate and ventilatory frequency, as well as hemolymphatic pH, pCO2 and pO2 were measured at different times throughout the experiment. Cardiac rate was significantly lower in crabs exposed to parathion, but only during the submersion periods, when cardiac activity is normally high. The insecticide could be affecting the neurological regulation of heart, avoiding the normal increase of cardiac activity. Ventilatory frequency, hemolymphatic, pH and gas parameters remained unaltered by exposure to 0.125 mg/L parathion, both under submersion and emersion. Key words: Parathion, cardiac rate, crabs, submersion, emersion.

Effects of seasonality and moult cycle on the proliferation of nerve cells and on the labelling of ecdysone receptors in an estuarine crab

Decapod crustaceans show proliferation of the nerve cells in the olfactory lobe throughout their lives. However, the regulation of this process is still poorly understood, since it may vary with endogenous and exogenous factors. The objective of the present investigation was to quantify the proliferation of nerve cells and number of nerve cells with ecdysone receptors in the clusters of the central olfactory system in Neohelice granulata, according to moult stages and in different seasons (summer and winter). Three injections of bromodeoxyuridine (BrdU) were administered to the crabs. Brains were sectioned by microtome and fixed on slides for immunohistochemistry with anti-BrdU and anti-EcR antibodies. The proliferation of nerve cells was higher in winter than in summer, probably because in winter the crabs do not breed and the premoult and postmoult periods are longer. Crabs in postmoult exhibited more BrdU-labelled cells than crabs in premoult or intermoult in winter, because of a greater number of mitoses related to an increase in body size and addition of olfactory receptor neurons. The number of EcR-labelled cells was higher in premoult than in postmoult or intermoult in winter. The proliferation of nerve cells is regulated seasonally and according to moult stages.

Claw Morphology and Feeding Rates of Introduced European Green Crabs (Carcinus maenasL, 1758) and Native Dungeness Crabs (Cancer magisterDana, 1852)

ABSTRACT Claw morphology and prey consumption rates of two estuarine crab species were compared: the introduced European green crab, Carcinus maenas, and the native Dungeness crab, Cancer magister. For crabs of similar weight, both the crusher and cutter claws of C. maenas were larger and exhibited higher mechanical advantage values of the claw lever system than C. magister. The mechanical advantages of C. maenas crusher and cutter claws are 0.37 and 0.30 respectively versus 0.25 for the claws of C. magister. To evaluate the feeding rates of similar-size crabs of each species on prey varying in shell thickness, we conducted laboratory feeding trials. Each crab was offered thin-shelled mussels (Mytilus trossulus, 30–40 mm) or thicker shelled native oysters (Ostrea lurida, 40–50 mm), and the number of consumed prey items was recorded. When offered mussels, subadult C. magister ate significantly more prey per day (7.2 prey/day) than adult C. maenas (5.4 prey/day). However, when crabs were offered harder shel...

Tn/T Specific Agglutinin from Estuarine Crab Scylla Serrata with Potent Mitogenic Activity on Mouse Splenocytes and Antiproliferative Effect on Hepatocellular Carcinoma (HepG2) Cell

A lectin was purified from the hemolymph of esturarine crab Scylla serrata by successive 40% (NH4)2SO4 precipitation, affinity chromatography on asialo fetuin- Sepharose column, Resource Q anion-exchanger in FPLC system and designated as scyllin-2. Scyllin-2 was a homogeneous monomeric protein of molecular mass 75 kD judged by SDS-PAGE and confirmed by ESI-MS-Q-ToF. Its activity was Ca+2 dependent being maximum at pH 7.5 and at 20 °C. N-terminal sequence of scyllin-2 showed close resemblance to peanut lectin and histidine kinase A. It agglutinated human O, A, B and AB blood group erythrocytes equally well and showed maxi- mum inhibition with α-Gal by hapten-inhibition study. The detailed carbohydrate specificity of scyllin-2 was determined at the macro-molecular level based on the Gal/GalNAc structural units in the mammalian glycoproteins by enzyme-linked lectinosorbent (ELLSA) and inhibition assays. It revealed that scyllin-2 binds specifically to tumor-associated carbohydrate antigens GalNAcα1→Ser/Thr (Tn) and Galβ1→3GalNAcα1→Ser/Thr (Tα). It showed very weak binding with Galβ1→3/4GlcNAc (I/II) glycotopes on glycoproteins and T/Tn covered by sialic acid. Multivalancy of Tn/Tα containing glycoproteins tested resulted in higher binding of 102–104 order than the respective Gal and GalNAc monomer. Scyllin-2 stimulated proliferation of mouse splenocytes. Analysis of expression of receptors for scyllin-2 on HepG2 by flow cytometry showed the binding of FITC-scyllin-2 to HepG2 was 86.51%, which was nearly comparable to Artocarpus lakoocha agglutinin (ALA) (66.41%), another Tn/Tα specific lectin indicating that the glycan structure on HepG2 cell surface shows prevalence of Tn/Tα units. It inhibited proliferation of HepG2 cells (61 µg/ml). The inhibitory effect was comparable to ALA (80 µg/ml). Thus, we have characterized a Tn/T specific invertebrate lectin with biological significance.

Thermogeography predicts the potential global range of the invasive European green crab (Carcinus maenas)

AbstractAim The highly adaptable estuarine crab (Carcinus maenas) has successfully invaded five temperate geographic regions outside of its native Europe. Here, we determine which environmental factors predict the current distribution of C. maenas and what the potential geographic range of this species might be. We also investigated whether the invasion potential of C. maenas differs with respect to the origin of a native subpopulation.Location Models were developed using global observation records of C. maenas.Methods Boosted regression trees were used to model observations from the (1) native, (2) invasive, (3) southern European, (4) northern European and (5) the combined native and invasive geographic ranges of C. maenas.Results Most established invasions were predicted mainly based on temperature. Interestingly, the environment encountered by established invasions failed to predict the majority of northern European populations; suggesting that invasion potential may differ between distinct native populations. Supporting this suggestion, a model of northern European populations, distinguished from southern European populations based on genetic structure, only predicted established invasions south of Nova Scotia. By contrast, a model of southern European populations predicted most established invasions.Main conclusions These results suggest that invasion potential depends on the European origin of an invasive population and that most invasions have arisen from southern Europe. Finally, a model based on combined native and invasive ranges of C. maenas identified potential geographic range extension along many currently invaded coastlines and the potential invasion of countries like Chile, China, Russia, Namibia and New Zealand.

Effects of zinc on molting and body weight of the estuarine crab Neohelice granulata (Brachyura: Varunidae)

The semiterrestrial burrowing crab Neohelice granulata is one of the main inhabitants of the supratidal and intertidal zones of brackish salt marshes, estuaries and coastal lagoons from South America's Atlantic littoral. A large population of this species spreads out Mar Chiquita coastal lagoon (in Argentina) and its corresponding wetlands, and is considered as a key species within this system. Since high values of dissolved heavy metals (including Zn) have been recently reported within Mar Chiquita coastal lagoon, with levels unusually higher than those from other coastal systems within Argentina, it has been explored that the existence of a risk of environmental conditions endanger these populations. So, juveniles of this estuarine crab were experimentally exposed to increasing concentrations of dissolved Zn (i.e., 0, 0.5 and 1 mg Zn 2+ L − 1 ) during six months, the time involved between two successive molts; in addition, both the size and weight reached after each molt were also studied in this assay. It can be concluded that zinc can be toxic to crabs only at high concentrations. Considering that levels up to 1 mg Zn L − 1 were recently reported in Mar Chiquita coastal lagoon waters, the potential occurrence of mean chronic effects on the crab population within the coastal lagoon is discussed.

Dietary copper effects in the estuarine crab, Neohelice ( Chasmagnathus) granulata, maintained at two different salinities

We analyzed the dietary copper effects in the estuarine crab Neohelice ( Chasmagnathus) granulata and its interaction with water salinity. Crabs were maintained at 2‰ and 30‰ salinity for 5 weeks and they were fed with commercial food supplemented with the green alga Scenedesmus vacuolatus previously exposed to copper. No mortalities were observed, but crabs maintained at 2‰ salinity accumulated on average 40% more copper compared to animals maintained at 30‰ salinity. At 2‰ salinity, superoxide dismutase (SOD) activity and reduced glutathione (GSH) levels were increased at the first and second weeks, respectively, while lipid peroxidation and protein oxidation were evident after 4 weeks of copper exposure. At 30‰ salinity, all measured variables increased progressively but were significantly higher only at the end of the assay (5th week), except for protein oxidation that remained unchanged throughout the experiment. The hepatosomatic index (HSI) was significantly decreased in response to copper exposure, but only in crabs acclimated to 2‰. These findings have suggested that dietary copper exposure induces greater metal accumulation and larger oxidative stress responses in crabs maintained at 2‰ salinity.

Effects of melatonin in connection with the antioxidant defense system in the gills of the estuarine crab Neohelice granulata

Numerous studies have shown that melatonin exerts some influence on the antioxidant defense system (ADS) in vertebrates, but for crustaceans no such effect has been demonstrated till now. However, earlier reports did show a similar profile of daily variations in the ADS of the gills and the melatonin content of the eyestalk in the crab Neohelice granulata and, thus, the aim of this study was to take a closer look at the effects of melatonin in the gill ADS of N. granulata. Gill ADS is to a minor extent modulated by reactive oxygen species (ROS), because only the nonproteic sulfhydryl (NP-SH) content increases ( p < 0.05) in the presence of hydrogen peroxide (H 2O 2). No significant differences ( p > 0.05) were observed in the melatonin content of the hemolymph between intact and eyestalkless crabs. Gills from intact and eyestalkless crabs injected with physiological saline showed a daily variation in the total peroxyl radical scavenging capacity (TPRSC) ( p < 0.05) with two peaks, one at the photophase and another at the scotophase. However, in the gills of eyestalkless crabs injected with melatonin (2 × 10 −12 mol crab −1), the daily variation in TPRSC values was abolished ( p > 0.05). This molecule did not change the NP-SH content ( p > 0.05) in vitro, but decreased ( p < 0.05) the oxygen consumption in gills when incubated for 120 min. In the in vivo experiments melatonin also decreased ( p < 0.05) the oxygen consumption in eyestalkless crabs after 390 min. The results suggest that melatonin does not act directly on the ADS of the gills of N. granulata, but decreases the aerobic metabolism possibly involved in variations of tissue ADS.

Alloxenic Distribution of Cystacanths of Two Profilicollis Species in Sympatric Crustacean Hosts in Chile

The taxonomic status of Profilicollis ( = Falsifilicollis Webster, 1948) species in crustaceans in Chile is examined. Mole crabs, Emerita analoga (Stimpson 1857), living in the splash zone of a sandy beach at Lenga off the coast of central Chile, harbor Polymorphus (Profilicollis) bullocki Mateo, Córdova and Guzmán 1982, while the estuarine crabs, Hemigrapsus crenulatus (Milne-Edwards, 1837), living in an oligohaline inlet at the same site, harbor Profilicollis spp. cystacanths which cannot be distinguished specifically to either Profilicollis antarcticus or P. chasmagnathi Holcman-Spector, Mañé-Garzón and Dei-Cas 1977. We found no morphological data supporting records of P. altmani along the coast of Chile. Therefore, and after examination of both their morphology and the literature, we consider that P. bullocki must be reinstated as a valid species in the genus. There is a widespread distribution of habitats, such as sandy beaches and inlets, as well as a variety of host taxa involved in the life cycle of Profilicollis spp. Consequently, they provide an interesting scenario for testing hypotheses regarding the coevolution and host specificity of these parasites.