Resumo em Inglês:

Abstract Until recently, three subspecies had traditionally been recognized in the astacid species Pacifastacus leniusculus (Dana, 1852): Pacifastacus leniusculus leniusculus, Pacifastacus leniusculus klamathensis (Stimpson, 1857), and Pacifastacus leniusculus trowbridgii (Stimpson, 1857). The type specimens attributed to these taxa were re-described with detailed illustrations of taxonomic characteristics for further taxonomic works.

Resumo em Inglês:

Abstract Flavalona asymmetrica sp. nov. belongs to the costata-clade. This species has two main head pores, a feature shared only with Flavalona setigera (Brehm, 1931). Morphological differences between them are related to main and lateral head pores, armature of scrapers on the second limb, and proportion of setae on the third and fourth limbs, number of denticles on the postabdomen. Males of F. asymmetrica sp. nov. has genital process about ten times shorter than length of postabdominal claw, which is an exclusive morphological trait. Flavalona asymmetrica sp. nov. is a Neotropical species, so far, it occurs only in Brazil and can be found together with Flavalona iheringula (Sinev & Kotov, 2004) and Flavalona margipluma (Sousa, Santos, Güntzel, Diniz-Filho, de Melo-Júnior & Elmoor-Loureiro, 2015).

Resumo em Inglês:

Abstract Shell occupation by the land hermit crab Coenobita violascens Heller, 1862 was investigated from January 2011 to March 2012 on Phuket Island in the Andaman Coast of Thailand. The samples of C. violascens were collected monthly using multiple quadrat sampling. Twenty shell species from 11 families were found occupying by C. violascens, which were mainly marine gastropods (90%). The three most common occupied shell species were Chicoreus brunneus (Link, 1807) (21.3% of hermits), followed by Filifusus filamentosus (Röding, 1798) (14.9%) and Laevistrombus canarium (Linnaeus, 1758) (14.9%). Biconical shells and those with ovate apertures were the most commonly occupied shell types. Furthermore, individual C. violascens probably occupy the shells of at least three different gastropod species during their lifetime. Interestingly, C. violascens shows a tendency of occupying specific categories of shells in relation to shell species, shape and aperture shape. Other aspects of shell occupation by C. violascens compared to congeneric species are also discussed.

Resumo em Inglês:

ABSTRACT The present study provides information on the morphology of stomatopod larvae found in two different reef systems which are also considered national parks: the Sistema Arrecifal Veracruzano (SAVNP) and Arrecife Puerto Morelos (APMNP). Zooplankton samples were collected at 26 stations of the SAVNP and four stations of the APMNP. Stomatopod larvae were identified and classified by their larval stage. We found representatives of three stomatopod superfamilies: the superfamily Gonodactyloidea Giesbrecht, 1910 was represented by Neogonodactylus oerstedii (Hansen, 1895), Neogonodactylus wennerae Manning and Heard, 1997, and Pseudosquillidae genus and species indeterminate; the superfamily Lysiosquilloidea Giesbrecht, 1910 was represented by Lysiosquilloidea genus and species indeterminate, Lysiosquilla sp., Lysiosquilla scabricauda (Lamarck, 1818) and Nannosquilla adkisoni Camp and Manning, 1982; the superfamily Squilloidea was represented by larvae of Alima neptuni (Linnaeus, 1768), Squilla spp., and Squilla empusa Say, 1818. We were able to identify and describe four stages of larval development for representatives of these superfamilies. This is the first study describing several stages of larval development of different species of the stomatopods from the Gulf of Mexico and Caribbean Sea.

Resumo em Inglês:

Abstract Five species of cladocerans are reported from the Tomo River, Vichada, Colombia. Zooplankton samples were collected from the littoral zone with vegetation (Campsiandra comosa Benth). Three of them, namely Streblocerus pygmaeus Sars, 1901, Disparalona cf. hamata (Birge, 1879) and Alona isabellae Sousa, Elmoor-Loureiro and Santos, 2016 are new to the Colombian cladoceran fauna. Descriptive notes, comparative comments on morphology and variability and illustrations are also provided for some remarkable taxa. This is the first report on the cladoceran fauna in the Tomo River.

Resumo em Inglês:

Abstract Ludwig Buckup holds a Bachelor’s degree in Natural History in 1954 from the Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, and a Ph.D. in Zoology from the University of Tübingen, Germany, in 1958. He joined UFRGS as a Professor in 1958, from where he retired in 1990. During this period he was fully devoted to his career of professor and scientist. His investigations in the area of Carcinology covered mainly the Parastacidae and Aeglidae families. Even after he retired, Professor Buckup participated in numerous research and extension activities inside and outside the University. Always engaged in environmental causes, he actively takes part in debates and lectures about the environment and conservation in the city of Porto Alegre and other cities in the state of Rio Grande do Sul. His career is highlighted by important steps for the construction of academic spaces and the development and consolidation of Carcinology, in particular for the Brazilian Crustacean Society.

Resumo em Inglês:

ABSTRACT: We examined the individual growth of the burrowing crayfish Parastacus nicoleti (Philippi, 1882) based on a sample of 1,425 specimens. Individuals were collected monthly from November 1981 to December 1982, in the marshy wetlands of the “Pangal” homestead in Reumen, southern Chile. The Cephalothorax Length (CL) and Body Weight (BW) were recorded for all specimens. The asymptotic length parameters (L ∞) and the growth coefficient (k) were established using the Gulland and Holt method (1959). The t 0 parameter was obtained through the inverse von Bertalanffy equation and the length-weight relationship was determined according to the equation proposed by Ricker (1975). The asymptotic size and weight were 45.754 mm and 18.50 g, respectively. The growth constant was 0.703/year. Estimated longevity was 4.32 years. We concluded that P. nicoleti is a relatively small species with poor growth indicators for size and weight and, consequently, is not an attractive species for commercial aquaculture purposes.

Resumo em Inglês:

ABSTRACT: The species composition and distribution of the pseudothelphusid and trichodactylid freshwater crabs from the state of Roraima, Brazil, are updated based mainly on documented records deposited in the collections of the Instituto Nacional de Pesquisas da Amazônia (Manaus) and the Museu Integrado de Roraima (Boa Vista). This paper provides records for the occurrence of ten species (six Pseudothelphusidae, four Trichodactylidae). Three species are recorded from Roraima for the first time: the pseudothelphusids Fredius beccarii (Coifmann, 1939) and Fredius fittkaui (Bott, 1967), and the trichodactylid Moreirocarcinus laevifrons (Moreira, 1901). The records of F. beccarii also represent the first documented occurrence of the species in Brazil. All species in the state are presented in maps that document their geographic distribution. Comments are made on the diversity of the Branco River crab fauna in comparision with diversity in other sub-basins of the Amazon River.

Resumo em Inglês:

ABSTRACT A survey of the invertebrate fauna of coral reef hard bottom communities in the shallow waters of Isla del Coco yielded a new species of mysid belonging to the genus Heteromysis S. I. Smith, 1873. Heteromysis (Olivemysis) cocoensis, n. sp. was collected from coral rubble at depths of 8 to 34 m. It differs from its congeners by having male pleopods 1, 3, and 4 with modified setae. Within the subgenus Olivemysis Băcescu, 1968, the new species is morphologically most similar to Heteromysis. ekamako Wittmann and Chevaldonne, 2017 from the Pacific, Heteromysis. gomezi Băcescu, 1970, H. mayana Brattegard, 1970, and H. rubrocinta, Băcescu, 1968 from the Western Atlantic, and Heteromysis. dardani Wittmann, 2008, Heteromysis. wirtzi Wittmann, 2008, and Heteromysis. sabelliphila Wittmann and Wirtz, 2017 from the Eastern Atlantic. However, H. cocoensis n. sp. is distinguished from these six apparently closely related species by the following combination of characters: flagellate, modified setae on articles 1 and 3 of the antennular peduncle, and setation of thoracic endopod 3, male pleopods 1, 3 and 4, uropodal endopods, and the apical and lateral margins of the telson. A diagnostic table separating these eight species is given.

Resumo em Inglês:

ABSTRACT Macrobrachium olfersii (Wiegmann, 1836) is a prawn that lives in shallow and transparent freshwater in Southern Brazil. Aquatic organisms that inhabit these systems can be exposed to incident UV radiation. Many studies have demonstrated the effects of ultraviolet (UV) radiation on the development, survival rate, morphological abnormalities, and impairments in swimming behavior in crustaceans. However, fewer studies have elucidated how the embryos of crustaceans respond to the exposure of UV radiation. Thus, the aim of this study was to evaluate whether UVA and UVB affect biometrical and morphological parameters of eggs and embryos of M. olfersii. Embryos were divided into two groups: Group I, composed of embryonic day 7 (E7) to E10 and Group II, composed of E11 to E14. Both groups were irradiated with 60 min UVA and 30 min UVB. Non-irradiated embryos at the same stages were used as controls. UVA and UVB radiation induces variations in morphometric parameters, such as egg volume, egg water content, and eye index. UVB radiation also induced an increase of embryonic cell death. We conclude that the embryonic cells of M. olfersii respond differentially to UVA and UVB radiation in accordance with the evaluated parameters.

Resumo em Inglês:

ABSTRACT The genus Alloniscus Dana, 1854 includes 23 known species occurring exclusively in littoral habitats. The genus has never been recorded from the Atlantic coastal region of the Americas. This work describes the new species Alloniscus buckupi n. sp. from João Pessoa, Paraíba, Brazil, and provides the first record of the genus from the Atlantic coastal region.

Resumo em Inglês:

Abstract Two new species of Parastacus Huxley, 1879 are described from the Atlantic Forest in southern Brazil: Parastacus buckupi sp. nov. from a highland stream in the hydrographic basin Maquiné river, Maquiné, state of Rio Grande do Sul; and Parastacus pilicarpus sp. nov. from a first order stream in the hydrographic basin Araranguá River, Morro Grande, state of Santa Catarina. Parastacus buckupi sp. nov. is distinguishable from all other Parastacus species via its large and globose chelipeds, by the presence of tufts of long and simple setae in the cutting edge of cheliped fingers, which are more abundant proximally and by possessing a telson with an acute distal margin. Parastacus pilicarpus sp. nov. is diagnosed mainly by the distal portion of the carpus which possess tufts of long, simple setae, and by having an epistome whose anteromedian lobe is heptagonal and as long as it is wide. Finally, P. pilicarpus antennal scales lateral margin terminates in a very strong terminal spine and mandibles incisive lobe has nine teeth, with the first tooth from the anterior margin being the largest. The conservation status based on the sub-criterion B1 of IUCN Red List allowed us to classify these species as “ENDANGERED” and “DATA DEFICIENT”, respectively.

Resumo em Inglês:

Abstract The aim of this study is to estimate the population size of Aegla longirostri Bond-Buckup and Buckup, 1994 in a subtropical low-order stream using the mark-recapture technique. We also tested if the Bayesian model is a promising estimator of population size. Data were collected in two periods, in spring 2010 (seven-day sampling) and in fall 2011(five-day sampling). The animals were sexed, measured, marked in the field, and released in the same spots from which they were collected. During the study period, 445 adults were captured (343 in the spring and 102 in the fall). The estimated population size was 1,005-1,028.8 individuals in the spring and 234-236 in the fall, according to the Schumacher-Eschmeyer and Schnabel methods, respectively. The estimated population size using the Bayesian analysis was 950.13 individuals in the spring and 210.08 in the fall. Although the Bayesian model is a more conservative approach, all methods showed similar and relevant estimations of population size.

Resumo em Inglês:

Abstract We present herein the results of a brief field survey of species of Macrobrachium Spence Bate, 1868 in three points of the northern portion of the lower Parnaíba River basin. The northern region of the lower Parnaíba River basin is part of the Environmental Protection Area Delta do Parnaíba and comprises several lakes, coastal lagoons, and the delta of the Parnaíba River. In total, we found five species: Macrobrachium acanthurus (Wiegmann, 1836), Macrobrachium amazonicum (Heller, 1862), Macrobrachium carcinus (Linnaeus, 1758), Macrobrachium jelskii (Miers, 1877), and Macrobrachium olfersii (Wiegmann, 1836) all of which are new records for the region.

Resumo em Inglês:

Abstract For the past 10 years, studies have contributed greatly to knowledge regarding the composition and distribution of the planktonic cladocerans of Tupé Lake in Amazonas State, Brazil, but comparisons between these studies have not been made, and this would increase the comprehension of the ecology of these organisms and their environment. Periodically the hydrological conditions in Tupé Lake change, due to its connecting channel with the Negro River. The purpose of this study was to determine the composition, abundance and diversity of cladocerans in the limnetic zone of Tupé Lake and compare the results with previous studies performed there. Samples were taken in April, June, September, October, November/08 and February/09 in 4 stations located in different areas of the lake. Ceriodaphnia cornuta G.O. Sars, 1886, Bosminopsis deitersi Richard, 1895 and Bosmina cf. longirostris (O.F. Müller, 1785) were the most abundant and frequent species of cladocerans among the 25 recorded species. Higher abundance and richness were observed during the low water phase (October/08). A relationship between the number of samples taken, as well as the type of sampling gear used, and the species richness was observed, when comparing this and previous studies performed in the lake.

Resumo em Inglês:

Abstract Mantis shrimps are prominent predatory crustaceans. Their larvae, although morphologically very differently-appearing from their adult counterparts, are already predators; yet, unlike the adults they are not benthic. Instead they are part of the plankton preying on other planktic organisms. Similar to some types of lobsters and crab-like crustaceans the planktic larvae of mantis shrimps can grow quite large, reaching into the centimeter range. Nonetheless, our knowledge on mantis shrimp larvae is still rather limited. Recently new types of giant mantis shrimp larvae with “extreme morphologies” have been reported. Here we describe another type that qualifies to be called “extreme”. Comparative measurements of certain morphological structures on selected known larvae support the exceptionality of the new specimen. It differs in several aspects from the original four types of extreme mantis shrimp larvae described by C. Haug et al. (2016). With this fifth type we expand the known morphological diversity of mantis shrimp larvae and also contribute to our still very incomplete, although growing, knowledge of this life phase.

Resumo em Inglês:

Abstract The century-old mangrove crab Ucides cordatus Linnaeus, 1763 harvesting is a traditional activity of Northeastern Brazilian coastal communities, who use it as food, source of income and cultural reference. The extractivism and marketing of this crustacean is essential for the socio-economic development of the states of Maranhão, Piauí and Ceará. The aim of this study was to carry out the monitoring of harvesting and landing of the mangrove crab in Ilha Grande, PI. Interviews were conducted with crab gatherers and transporters to obtain information about harvesting, landed volume, market price and destination of commercialized crab. The main capture spots were located at the Maranhão part of the Parnaíba River Delta. Crab gatherers are active 5.07 times a week and spend an average of 6 hours in mangrove. The average number of crabs collected per gatherer/day was 77.0. The quantity landed in daytime period was 63,628 crabs/month, totalizing 714,543 crabs/year. The average price traded was USD 0.19/crab. The production chain of mangrove crab harvesting requires planning for maintain the natural stocks and aggregation of value to the product, benefiting the appreciation of crab gatherers.

Resumo em Inglês:

ABSTRACT Aeginecta longicauda n. gen., n. sp. is described from material collected from a seasonally astatic aquatic habitat in Argentina. It is only known from the type locality and two male specimens; at this point the female remains unknown. Specific unique gonopod and genital segment features demonstrate that this taxon represents a unique genus within the Thamnocephalidae. Aeginecta n. gen most closely resembles Phallocryptus Biraben, 1951 and Thamnocephalus Packard, 1877. This new genus is easily diagnosed by the compound eye peduncle being extremely short, the frons and anterior surface of antennae II broadened laterally, with an intervening slit through which the compound eye may view the area forward on the animal, and the cercopods are as long as the abdomen. The gonopod proximal portion is bulbous with a transverse cleft, and projects ventrally from the segment. The gonopod distal eversible portion is minute, lamellar, and lies within proximal portion cleft. This is the fifth thamnocephalid genus reported from South America. The Neotropical region has the greatest thamnocephalid generic diversity in the world.

Resumo em Inglês:

Abstract The pet trade is a significant source of introductions of non-indigenous aquatic species, such as crayfish. To test whether legislation that regulates the ownership of ornamental animals for aquariums had the desired effect of reducing the availability of those pets, classified advertising websites were monitored for sales of crayfish in jurisdictions with and without legislation regulating the ownership of crayfish. Advertisements from Canadian provinces with legislation against owning crayfish were compared to provinces without such legislation. The population adjusted number of advertisements for crayfish, and number of distinct sellers of crayfish, was significantly lower in one of two provinces that prohibited crayfish compared to provinces that permitted crayfish. This mixed outcome suggests that legislation alone does not consistently reduce online trade in crayfish.

Resumo em Inglês:

Abstract The morphology of the foregut ossicles of representatives of four genera of Dilocarcinini were described to assess the usefulness of the ossicles as possible morphological characters in studies on the intrafamilial relationships of Trichodactylidae. Stomachs of specimens of Dilocarcinus pagei Stimpson, 1861, D. septemdentatus (Herbst, 1783), Moreirocarcinus emarginatus (H. Milne Edwards, 1853) and M. laevifrons (Moreira, 1901) were heated for 60 minutes in 10% KOH solution and then were stained with Alizarin Red 1% added into the KOH solution. The foregut ossicles of Dilocarcinini consists of 11 ossicles of the gastric mill, 10 of the lateral supporting cardiac region, 4 of the cardio-pyloric valve, 6 supporting the dorsal pyloric stomach, 9 supporting the ventral pylorus and bulb, 3 supporting the supra-ampullary region, 5 supporting the lateral pylorus region, totaling 48 ossicles and the following 34 are similar in shape, size and degree of calcification. The morphological differences between the majority of the ossicles were not very clear among the species, showing inconsistency intrageneric differences, however, species of different genera showed small similarities between them. There is a clear need for including more taxa in a comparative analysis, combined with external morphology and perhaps even molecular data to properly evaluate the phylogenetic relationships within Trichodactylidae and their systematic position within Brachyura.

Resumo em Inglês:

Abstract Two recently described amphipods species from southern Brazil, Hyalella georginae Streck and Castiglioni, 2017 and Hyalella gauchensis Streck and Castiglioni, 2017, had their population structures characterized by sex, females’ ovigerous condition, cephalothorax length (mm), size-class frequency distribution, sex-ratio, reproductive period, and recruitment. The specimens were collected with a dip net from a stream source (H. georginae) and from a water reservoir (H. gauchensis) in the Palmeira das Missões municipality, state of Rio Grande do Sul, Brazil, from August 2012 to July 2013 (12 months). Both species showed a bimodal frequency distribution for total and seasonal size classes, with males larger than females. Overall, the sex ratio favored females when analyzed monthly and seasonally. Ovigerous females were recorded throughout the year, with higher frequency in spring (H. georginae) and summer (H. gauchensis), characterizing a seasonal reproduction. Both species showed continuous recruitment, with greater intensity in the spring. The population structure of these two Hyalella species had similar features, showing continuous recruitment and seasonal reproduction related to their life-history strategies, which promote adaptations to their habitat.

Resumo em Inglês:

Abstract We determined the infestation rate of Probopyrus sp. in populations of Palaemon pandaliformis (Stimpson, 1871) and P. northropi (Rankin, 1898) in the Ubatumirim River, localized in a mangrove ecosystem on Ubatumirim Beach, northern coast of the state of São Paulo, Brazil. Samplings were carried out monthly from April 2003 to March 2004. Monthly prevalence varied from 0 to 4.94 % for P. pandaliformis, and from 0 to 4.54 % for P. northropi. This is the first record of Probopyrus sp. infesting the studied species in this region. Species of Probopyrus (Giard and Bonnier, 1888) seem to have a high plasticity with regard to palaemonid hosts, as they can be parasites of shrimps in both Palaemon (Fabricius, 1798) and Macrobrachium (Spence Bate, 1868). The linear relationships between the parasite and host sizes suggest that the parasite infests both hosts early in their development. We concluded that the infestation of Probopyrus sp. has little impact on Palaemon populations, mostly due to the low prevalence of infestation.

Resumo em Inglês:

ABSTRACT The distributional patterns of 13 species of Diaptomus Westwood, 1836 were analyzed using the panbiogeographical method of track analysis. Locality records were compiled from the literature and mapped for the construction of individual tracks for each species. These tracks were superimposed to find the generalized tracks. Four generalized tracks were found: (1) Siberia, Central Europe, and Iceland; (2) Northern Italy, southern France, central Spain, northern Algeria, and northern Morocco; (3) Southern France, central Spain, and northern Morocco; (4) Southern Italy, Sicily, and Albania. Five biogeographic nodes were found: (A) Southwestern Iberia, (B) Southeastern Iberia, (C) Central Iberia, (D) Cantabria, at the intersections of generalized tracks 2 and 3; and (E) Italian Peninsula Islands, at the intersection of generalized tracks 2 and 4. The main massing of the species of Diaptomus studied is located in the Iberian peninsula, where six of the species do occur. A model based on the fragmentation and differentiation of already widespread ancestors during the late Mesozoic and early Cenozoic, related to the opening the North Atlantic Ocean and the formation of the Mediterranean Sea, is proposed as a most parsimonious explanation for the observed patterns of geographic vicariance.

Resumo em Inglês:

Abstract We describe a new species of freshwater crab, Aegla chilota, from two small streams at Yaldad Bay, in the southern end of Chiloé Island, western Patagonia. The new taxon is distinguished from the remaining Chilean species of Aegla Leach, 1820 by the following morphological diagnostic features: rostrum neatly triangular, short, scarcely surpassing eyes; orbital sinus wide, shallow, limited by tiny extra-orbital spine and wide extra-orbital sinus; carpal lobe prominent, triangular, tipped by at least two coalescent acute conical scales; second abdominal epimeron little produced, armed with acute scale; telson plate roughly pentagonal, with functional median suture. Molecular phylogenetic analyses also support the separation and diagnosis of A. chilota from its sister taxon, A. hueicollensis Jara and Palacios, 1999. The type locality for A. chilota n. sp. is a small river that drains a small hilly portion of the south-eastern coast of Chiloé Island; the other river in which the species was found is isolated from the type locality by the Yaldad Bay into which both rivers drain.

Resumo em Inglês:

ABSTRACT The objective of this study was to describe the morphology of Clibanarius antillensis Stimpson, 1859 megalopae collected in the vicinity of Isla Sacrificios, Mexico, and compare it to previous descriptions originated from Brazilian and Panamanian specimens raised in laboratory conditions. We found four meristic differences between the Brazilian and the Panamanian and Mexican populations with the Brazilian population: the outer flagellum of antennule in the Panamanian and Mexican populations has more aesthetascs on the second, third, and fourth segments of the outer flagellum (0, 6, 5, 3, 0) than the Brazilian population (0, 4, 4, 2, 0); the maxilla has more setae on the scaphognathite in the Brazilian specimens (70) than in the Mexican and Panamanian specimens (49-62); the crista dentata of the third maxilliped is formed by only three denticles in the Brazilian specimens, while 4 or 6 denticles form the same structure in the Panamanian and Mexican populations; there are fewer number of setae on the endopod of the uropod in the Brazilian population. The differences may be explained by intraspecific variation.

Resumo em Inglês:

Abstract Based on an updated checklist of the benthic caridean shrimp fauna of the Eastern Tropical Pacific (ETP), we analyzed their large-scale species richness distribution patterns using a grid approximation. Caridean fauna is composed of 183 species belonging to 67 genera and 18 families. Alpheidae, Palaemonidae and Thoridae contributed largely to species richness. Alpheus and Synalpheus were the most diverse genera. Most species (24%) have a narrow distribution inhabiting a single grid, and as many as 135 are restricted to < 5 grids. Mexico has the largest richness (130) besides Ecuador (98) and Panama (75). Richness among grids varies largely; overall, it is larger around Galapagos and Panama, Colombia, Costa Rica and the Gulf of California. There was a meaningful correlation between a proxy of sampling intensity and richness, suggesting that along with habitat heterogeneity or large-scale evolutionary processes currently invoked as richness drivers, the pattern can also be related to differences in research efforts. Exponential fitting and Chao2 index suggest that the caridean faunal inventory from the ETP is still far from being complete. Overall, the results call for a more thoughtful and systematic sampling scheme in order to get information from poorly sampled environments and areas in the ETP.

Resumo em Inglês:

Abstract A series of specimens of the fish external parasite Rocinella murilloi Brusca and Iverson, 1985, is reported from 12 localities off western Mexico. These records are the first for southwestern Mexico (four) and add six new localities off the west coast of the Baja California Peninsula where the species was known from a single record. The specimens were recovered from bottom-operated nets, between 700 and 1235 m, slightly shallower than previous records. Environmental conditions confirm the presence of R. murilloi below the core of the Oxygen Minimum Zone, and this species appears to be highly tolerant to moderate to severe hypoxic conditions. General distribution of the species in the eastern Pacific is presented.

Resumo em Inglês:

ABSTRACT A checklist of the order Mysida from Pulau Tinggi, Sultan Iskandar Marine Park, Johor, Malaysia is presented. With the aid of an epibenthic sledge, a total number of 9,239 mysids were collected during years 2012-2013 from two fixed stations of seagrass bed in Pulau Tinggi. So far there are 13 species, 10 genera, and 6 subfamilies of mysids. Of these, one species Siriella media Hansen, 1910 is recorded as new to Pulau Tinggi. The checklist presented herein includes the reference to each species’ original description, type locality, information on geographical distribution.

Resumo em Inglês:

Abstract All species of Brazilian terrestrial isopod known up to date, including references and distribution information, are listed. The list comprises 189 valid species, 135 of which are endemic to the country, 22 are recorded also from other countries in the Americas, 20 are introduced, and 12 have circumtropical or pantropical distributions.

Resumo em Inglês:

Abstract Infrequently studied coral species are seldom mentioned as host organisms of associated fauna. Here we report on the stony coralAgaricia tenuifoliaDana, 1848 hosting a gall crab (Cryptochiridae) for the first time. This coral-dwelling crab was observed at the southern coast of Bonaire in the Dutch Caribbean. Based on the shape of the dwelling, and the host specificity of cryptochirids, the crab is tentatively identified asOpecarcinus hypostegus(Shaw & Hopkins, 1977).

Resumo em Inglês:

Abstract Apart from traditional characters, other data have been used for taxonomy, like color patterns. Based on the different colors (green and orange) observed for some Calcinus tibicen (Herbst, 1761) specimens, we evaluated the genetic distance for cytochrome oxidase subunit I mitochondrial gene of individuals collected in Pernambuco (northern Brazil) and in São Paulo (southeast Brazil). We found low genetic variation (0.2-1.1%), and no evidence of isolation on our molecular tree based on genetic distance. We suggest high levels of gene flow between specimens with different color patterns, which are polymorphisms and might be related to the kind of nutrition as well different ecological and evolutionary predation characteristics.

Resumo em Inglês:

Abstract The occurrence of intersex specimens of Lissoporcellana quadrilobata (Miers, 1884), Pisidia bluteli (Risso, 1816) and Pisidia longimana (Risso, 1816) is recorded for the first time and their secondary sexual characters analyzed. Intersex specimens were collected in regions regularly affected by pollution. There is a high possibility that intersexuality in porcelain crabs is caused by environmental contamination.

Resumo em Inglês:

Abstract Sensitivity to different concentrations (0-200 mgL-1) of the alkylating agent methyl methanesulfonate (MMS) was evaluated in the new potential invertebrate model, the amphipod Quadrivisio lutzi (Shoemaker, 1933) after 48 h of exposure in two separate bioassays. In the first bioassay (0, 50, 100 and 200 mgL-1 MMS), all amphipods at concentrations ≥ 50 mgL-1 MMS were dead before completing the 48 h of exposure, which was also observed in the second bioassay for concentrations ≥ 30 mgL-1 MMS. There was no significant effect of gender on average mortality. The median 48 h lethal concentration (LC50) was 23.6 mgL-1 MMS for Q. lutzi. Therefore, 1/3 or less of this concentration may be used for positive control in sublethal conditions. The high sensitivity of Q. lutzi to MMS is discussed in comparison to other invertebrates.

Resumo em Inglês:

Abstract Two species of isopods of the family Idoteidae were collected in the same sample, among sea grasses, in the northern Gulf of California, Mexico. The first species, Synidotea harfordi Benedict, 1897, was more abundant (46 specimens) than the second species, Eusymmerus antennatus Richardson, 1899 (eight specimens). Synidotea harfordi has previously been considered uncommon in the Gulf of California, and more like a component of warm-temperate to colder-water fauna. The male of E. antennatus has not been illustrated but SEM photographs are provided and show angular margins of the first three pereonites and a sharply bent lateral margin of the telson. Females also have angular first pereonites. All previous illustrations show rounded pereonites margins. Buccal appendages of E. antennatus are illustrated and compared with previous descriptions.

Resumo em Inglês:

ABSTRACT The cliff crab Plagusia depressa (Fabricius, 1775) is recorded for the first time from the state of Sergipe, northeastern Brazil. This new record fills the gap in the species distribution between Pernambuco (8°S) and Bahia (12°S).

Resumo em Inglês:

Abstract The present study describes the first record of bilaterally hypertrophied chelipeds in a male fiddler crab, Minuca rapax (Smith, 1870), collected in the mangrove area near the city of Jaguaribe, located in the northern portion of Itamaracá Island in Pernambuco, Brazil. This particular specimen was captured by hand as it emerged from its burrow. Of the total 126 individuals (48 females and 78 males) of the genus Minuca (Bott, 1954) captured, only one presented chelipeds similar in size and shape. Some of the causes of malformation in decapods have been attributed to a double generation of growth areas or non-synchronous regenerative coordination in wound healing. Due to the lack of studies on the definitive cause of these abnormalities and deformations, further investigations are required to determine the roles of individuals with abnormalities within populations as well as the principal causes of these abnormalities.

Resumo em Inglês:

Abstract Kisakiellus aweti Sousa and Elmoor-Loureiro, 2018 (Cladocera, Chydoridae) was described from first-order streams in Upper Xingu River basin. Here, we report a new occurrence of this species from Araguari river, Amapá, Brasil, extending its distribution range for more than 1,500 km in Amazon Hydrogeographic Region.

Resumo em Inglês:

Abstract The present study provides a list of the freshwater crab species of the family Trichodactylidae recorded from the state of Maranhão, northeastern Brazil, along with information about their distribution. Eight streams were sampled with dip nets, sieves, gill nets, and drag nets. Four species were found: Dilocarcinus septemdentatus (Herbst, 1783), Goyazana castelnaui H. Milne Edwards, 1853, Sylviocarcinus pictus (H. Milne Edwards, 1853), and Valdivia serrata White, 1847. Our results increase the known distribution range of these species and add new records to more basins.