Abstract Heterochely is an important phenomenon in decapod crustaceans. Nevertheless, it was rarely examined in freshwater crayfish. Therefore, the aim of this study was to investigate cheliped loss and abnormalities of the narrow-clawed crayfish, Pontastacus leptodactylus. The crayfish samples were captured using 17 mm mesh-sized fyke-nets from Atikhisar Reservoir in Çanakkale, Turkey between July 2020 and June 2021. The cheliped loss was classified and compared between sexes and length groups. The cheliped surface was calculated for each specimen for both the right and left cheliped. Results of the study indicate that the percentages of the sampled individuals were 5.46% for the right cheliped missing group, 5.23% for the left cheliped missing group, 10.37% for both chelipeds missing group, and 78.94% for both chelipeds present group. There was a statistical difference between cheliped loss and size groups (p < 0.05). Although cheliped loss is almost non-existent in low-size groups (10.0-29.9 mm), it reaches high values in the 40.0-69.9 mm size groups. The most intense loss occurs in the 40.0-49.9 and 50.0-59.9 mm size groups. It was determined that 10.69% of the sampled individuals examined had a single cheliped (10.03% female, 11.14% male). A statistically significant difference was found between cheliped loss and sex (p < 0.05). The percentage of female and male individuals with no chelipeds is 9.83% for females and 10.73% for males, and with both chelipeds it is 80.14% for females and 78.14% for males. While the number of abnormalities observed in chelipeds was higher in males, abnormalities in both chelipeds were higher in females. Moreover, it was found that cheliped loss significantly differed according to the months of collection (p < 0.05). Cheliped losses increased in July, August, and September when feeding was comparatively intense. In conclusion, the fact that the individuals were obtained alive, was an indication that the abnormalities detected did not significantly affect their vital activities directly. However, morphological abnormalities in the appendages, especially in the chelipeds, may impair their functional use compared to a healthy cheliped. This abnormal condition is assumed to share the disadvantageous limitations experienced by the absence of a cheliped. crustaceans Nevertheless Therefore narrowclawed narrow clawed leptodactylus 1 meshsized mesh sized fykenets fyke nets Çanakkale 202 2021 546 5 46 5.46 group 523 23 5.23 1037 10 37 10.37 7894 78 94 78.94 p 0.05. 005 0.05 . 0 05 0.05) nonexistent non existent lowsize low 10.029.9 100299 10.0 29.9 29 9 (10.0-29. mm, , mm) 40.069.9 400699 40.0 69.9 40 69 40.0-69. 40.049.9 400499 49.9 49 40.0-49. 50.059.9 500599 50.0 59.9 50 59 50.0-59. 1069 10.69 10.03% 1003 03 (10.03 1114 11 14 11.14 male. male) 983 83 9.83 1073 73 10.73 males 8014 80 80.14 7814 78.14 Moreover August conclusion alive directly However appendages 20 54 4 5.4 52 2 5.2 103 3 10.3 789 7 78.9 00 0.0 029 10.029. 10029 100 10. 299 29. (10.0-29 069 40.069. 40069 400 40. 699 69. 6 40.0-69 049 40.049. 40049 499 49. 40.0-49 059 50.059. 50059 500 50. 599 59. 50.0-59 106 10.6 10.03 (10.0 111 11.1 98 8 9.8 107 10.7 801 80.1 781 78.1 5. 78. 0. 02 10.029 1002 (10.0-2 06 40.069 4006 40.0-6 04 40.049 4004 40.0-4 50.059 5005 50.0-5 (10. 11. 9. 80. 10.02 (10.0- 40.06 40.0- 40.04 50.05 50.0- (10 (1 (

ABSTRACT The calanoid copepod family Epacteriscidae is one of the most representative cave-dwelling copepods worldwide, especially in the Caribbean region. We provide new records of two epacteriscid copepods from anchialine habitats of the Yucatan Peninsula (YP); both were previously known only from their type locality in Jamaica and Caicos Islands. We document the occurrence of Edaxiella rubra Fosshagen, Boxshall and Iliffe, 2001 in Cozumel Island and Bofuriella spinosa Fosshagen and Iliffe, 2007 in Playa del Carmen, the adjacent continental region of the YP. We found slight morphological differences compared to the original descriptions of both species, including some characters not previously described; also, the male of B. spinosa remained unknown and is herein described. These records show the growth of the epacteriscid copepod listings and expand the morphological knowledge of these species in the Yucatan Peninsula into the Western Caribbean, likely harboring one of the most diverse anchialine copepod fauna worldwide and currently going through intense anthropogenic pressure, thus enhancing the intrinsic value of these new findings. It is expected that new samplings will reveal the true diversity and distribution of the Mexican Caribbean anchialine copepod fauna, where knowledge of its biological diversity is still incipient. cavedwelling cave dwelling YP (YP) Islands Iliffe 200 Carmen described also B pressure findings incipient (YP 20 2

Abstract Despite the recent increase in knowledge about Brazilian Cladoceromorpha (Cladocera and Cyclestherida), this group of fauna is poorly known in some regions of the country, including Alagoas State. Based on the literature and a few original samples, the present paper reports 35 species of Cladoceromorpha from Alagoas, 18 of which are new records for the state. The observed taxa are illustrated. In addition, distributional and taxonomic comments on selected taxa are provided. Cladocera Cyclestherida, Cyclestherida , Cyclestherida) country State samples 3 1 state illustrated addition provided

Abstract The present paper describes a new species of freshwater crayfish of the genus Parastacus Huxley, 1879 from the municipality of Amaral Ferrador in the state of Rio Grande do Sul, southern Brazil, evaluates its conservation status according to the IUCN Red List Criteria (sub-criterion B1), and updates the identification key for the genus. Parastacus longidactylus sp. n. differs from all analyzed species by the large eyes, the prominent and wide rostral carinae, surpassing the rostral basis and extending to the proximal third of the postorbital carinae, postorbital carinae and rostral carinae prominent and with similar lengths, chelipeds carpus dorsomedial surface not divided longitudinally by groove and long dactylus, surpassing the fixed finger. The possible extent of occurrence was estimated to be 6,968 km² and the species was recorded in only one location in the Camaquã River basin. The main threats to the region are the replacement of native vegetation by crops and livestock, water pollution and soil erosion. However, because there is only one known location where Parastacus longidactylus sp. n. occurs we suggest classifying the species as Data Deficient. Huxley 187 Sul Brazil subcriterion sub criterion B1, B1 B , B1) sp n eyes lengths dactylus finger 6968 6 968 6,96 km basin livestock erosion However Deficient 18 696 96 6,9 1 69 9 6,

Abstract Intermediate metabolism and oxidative balance markers help to better understand environmental dynamics and how they influence the physiological patterns of organisms. Procambarus clarkii (Girard, 1852), a crayfish native to the United States of America and Mexico, represents an appealing case study for understanding invasive species’ metabolic dynamics. This species has sexual dimorphism and two male morphotypes: reproductive (M1) and non-reproductive (M2). We evaluated the seasonal variations of biomarkers in M1 and M2 males, collected in each season of 2016 at Parque Alfredo Volpi (São Paulo, Brazil). Hemolymph, hepatopancreas and abdominal muscle samples were extracted to determine markers of intermediate metabolism, oxidative balance, the hepatosomatic index and the stomach repletion degree. The results showed differences between the two male morphotypes. M1 showed a predominance of medium to full stomachs throughout the year, with an allocation of energetic substrates mainly used in reproduction (gametogenesis and reproductive behaviors). They also presented increased lipoperoxidation, SOD and GST activities. M2, on the other hand, had a lower capacity to allocate energy reserves in the period leading up to and during reproduction, which may be associated with a lower degree of gastric repletion. However, M2 maintained alternating antioxidant strategies that helped preserve low levels of lipoperoxidation in the hepatopancreas throughout the year. This pattern observed for the degree of gastric repletion indicates an intraspecific competition between the categories of males, which, together with the profile of energy reserve usage, seems decisive for M2 to reproduce. organisms Girard, Girard (Girard 1852, 1852 , 1852) Mexico morphotypes M (M1 nonreproductive non M2. . (M2) males 201 São Paulo Brazil. Brazil Brazil) Hemolymph year gametogenesis behaviors. behaviors behaviors) activities hand However usage reproduce 185 (M (M2 20 18 2 1

Abstract Isopods of the suborder Cymothoida include ectoparasite species that cause physical damage and affect the development of the host by feeding on blood and tissues. On fishes, these parasites attach themselves to the skin, fins, gills, and oral cavity using claws on articulated legs. The ability to remain hidden in cavities even after the fish is caught enables isopods to be transported to new areas along with the host, making these parasites potential co-invaders. Understanding the role and environmental impact of parasites is essential, although research on parasitism in the context of biological invasions lags in comparison to general research on such invasions. Previous records indicate only two species of parasitic isopods in the São Francisco River basin. However, the present study reports the first record of two other species (Braga patagonica and Braga nasuta) on Pygocentrus piraya and in the basin itself. This demonstrates a lack of knowledge regarding fish parasites in the region, despite the presence of other parasites. Collaborations with research groups conducting fish sampling in the basin can contribute to expanding knowledge on these parasites and the training of human resources in fish parasitology. The present study provides important information on the presence of unidentified parasitic isopods on fishes in the São Francisco River basin, underscoring the need for further studies and expanding the geographic distribution of these parasites, as well as the host list for these isopods. tissues skin fins gills legs coinvaders. coinvaders co invaders. invaders co-invaders essential However nasuta itself region parasitology

Abstract Herpyllobiid copepods are highly transformed mesoparasites that infect marine benthic polychaete annelids. The genus Herpyllobius Steenstrup and Lütken, 1861, the most diverse in the family, was known to infect exclusively polychaetes of the family Polynoidae, but it was recently reported also on another family. Species of Herpyllobius have been reported mainly from cold latitudes including Arctic and Antarctic areas, except for two subtropical species. During the taxonomic examination of flabelligerid polychaetes collected from a Western Australian coral reef system, a mesoparasitic copepod was found infecting a specimen of Lamispina horsti (Haswell, 1892). The copepod represents an undescribed species of Herpyllobius. The new species, Herpyllobius paulayi n. sp. belongs to a group of congeneric species (Group III) lacking intergenital processes or sclerotized dots. It diverges from the other species in this group by its possession of a unique combination of characters: 1) a globose ectosoma with pilose surface; 2) elongate, thick cylindrical egg sacs with +10 egg rows; 3) endosoma discoid, short, with two lateral, asymmetrical flattened processes and a medial lobe; 4) it attaches to the host prostomium; and 5) it infects a non-polynoid subtropical polychaete species. annelids Lütken 1861 Polynoidae areas system Haswell, Haswell (Haswell 1892. 1892 . 1892) n sp Group III dots characters 1 surface 2 elongate 10 +1 rows 3 discoid short lateral lobe 4 prostomium 5 nonpolynoid non polynoid 186 189 + 18

Abstract The natural history and conservation status of the West Indian endemic freshwater crabs of the genus Epilobocera are poorly known. Several species have restricted distributions and apparently specific ecological requirements, which make them particularly vulnerable to anthropogenic threats. Epilobocera capolongoi is known to occur exclusively in mountain streams and rivers above 300 m elevation in the Guamuhaya Massif, central Cuba. In addition to the publication with the original description, there is only one paper exclusively on this species, which reported it as being preyed upon by a heron and recorded it from some additional localities in the vicinity of Topes de Collantes, provinces of Cienfuegos and Sancti Spíritus. Epilobocera capolongoi is herein reported from Pico San Juan Ecological Reserve and Lomas de Banao Ecological Reserve, which expands its geographic range to about 60 km and its elevation to 1,000 m. The species was found living sympatric with the congeneric Epilobocera cubensis poliorcetes in Lomas de Banao Ecological Reserve, but apparently there exists some habitat segregation between them. Some phenotypic characters important to distinguish both species are described, some basic data on their natural history are provided, and an assessment of the conservation status of E. capolongoi following current IUCN criteria is made. requirements threats 30 Massif Cuba description Collantes Spíritus 6 1000 1 000 1,00 described provided E made 3 100 00 1,0 10 0 1,

Abstract A new podocerid amphipod, Leipsuropus seisuiae sp. nov., from 338-340 m depth in the Kumano Sea, Japan, Northwestern Pacific, is described. This is the deepest record of any Leipsuropus species. Leipsuropus seisuiae sp. nov. is distinguished from four other congeneric species in having: i) pereonites 2-5 each with five narrow spiniform projections on tergal plate, ii) one dorsal tubercle on the telson, and iii) one small, proximal, denticulate projection on gnathopod-2 palmar margin. A key to males of the species of Leipsuropus is provided. amphipod sp nov 338340 338 340 338-34 Sea Japan Pacific described having i 25 2 5 2- plate ii telson iii small proximal gnathopod2 gnathopod gnathopod- margin provided 33834 33 34 338-3 3383 3 338-

Abstract A body entirely covered with long and sharp-pointed spines makes Acanthoniscus spiniger Gosse, 1851, one of the rarest and most ornamented terrestrial isopods in the world. The original description of this species was based on a single specimen collected by the British naturalist Philip Henry Gosse in Jamaica in 1845 and deposited in the British Museum (currently The Natural History Museum, London). A second specimen, presumably of this species, was collected by the American entomologist Henry Guernsey Hubbard in 1877 and deposited in the United States National Museum, Smithsonian Institution, which served as the basis for a further description by Richardson (1909). After Gosse and Hubbard specimens, no additional material appears to have reached any museum collection. Due to the scarce available information on this genus, it has been indistinctly placed in at least four different families through history, without a consensus on its definitive placement to date. Herein, we describe a new species of Acanthoniscus Gosse, 1851, based on a population discovered in the Blue Mountains, Jamaica, above 1,200 m elevation and more than 150 km eastward of A. spiniger’s type locality. We also emend the authorship and diagnoses of the genus Acanthoniscus and its type species. Finally, we discuss the possible relationships of Acanthoniscus at the family level, concluding that, despite some putative autapomorphies, it belongs to Armadillidae, as its present-day status. sharppointed sharp pointed 1851 world 184 currently London. London . London) 187 Institution 1909. 1909 (1909) specimens collection history date Herein Mountains 1200 1 200 1,20 15 spinigers s locality Finally level that autapomorphies Armadillidae presentday present day status 185 18 190 (1909 120 20 1,2 19 (190 12 2 1, (19 (1 (

Abstract Alpheus christofferseni Anker, Hurt and Knowlton, 2007 was described based on four specimens from Atol das Rocas, northeastern Brazil, and one specimen from Bocas del Toro, the Caribbean coast of Panama. Here, we report the collection of two specimens from Pernambuco, Brazil (~ 8°41’S), thus increasing the knowledge on species distribution along the Brazilian coast by approximately five latitudinal degrees south of its type locality (Atol das Rocas, Rio Grande do Norte, ~ 3°51'S). We also report a substantial increase in the known bathymetric distribution from shallow intertidal to approximately 51 m. Notes on morphological variation are provided based on the new material, and the first sequence of the 16S ribosomal subunit gene for the Brazilian coast is provided and compared with congeners. Anker Knowlton 200 Rocas Toro Panama Here Pernambuco ( 8°41S, 841S S 8°41 , 8 41 8°41’S) Norte 3°51S. 351S 3°51 . 3 3°51'S) 5 m material congeners 20 41S 8°41S 841 8°4 4 8°41’S 51S 3°51S 351 3°5 3°51'S 2 84 8° 35 3°

Abstract A new epigean asellid isopod, Caecidotea contrerasbalderasi sp. nov. is described from Nayarit, northwestern Mexico. This new species has morphological characters belonging to two different types of environments, both depigmentation and anophthalmia, indicators of organisms adapted to live in constant darkness as cavernicolous species. Despite showing characteristics of hypogean species, the new taxon does not show elongation of appendages, such as pereiopods, antennae or uropods. Its pleopod IV exopod lacks false sutures. This is a new pattern type “C”, and differs from that observed in types A and B. The description of this new species brings a new total of 101 species and three subspecies, for the genus Caecidotea in North America all morphologically poorly differentiated and with a restricted distribution. isopod sp nov Nayarit Mexico environments anophthalmia appendages pereiopods uropods sutures C, C , “C” B 10 subspecies distribution “C 1

Abstract The poorly known pilumnid, Vellumnus penicillatus (Gordon, 1930), is redescribed by examining the Hong Kong types. A new species, Vellumnus tki n. sp., is described from Macclesfield Bank, South China Sea, and it is distinguished from its closest congener, Vellumnus minabensis (Sakai, 1969) from Japan, by the setal pattern on the carapace and pereiopods, carapace proportions, structure of the front and anterolateral teeth, armature on the chelipeds and relatively shorter ambulatory legs. pilumnid Gordon, Gordon (Gordon 1930, 1930 , 1930) types species n sp sp. Bank Sea congener Sakai, Sakai (Sakai 1969 Japan pereiopods proportions teeth legs 193 196 19 1

Abstract The study investigated the population parameters of the shrimp Xiphopenaeus spp. (commonly known as seabob shrimp) in Anchieta, south coast of the state of Espírito Santo, Brazil, focusing on reducing the sampling effort. Shrimp were collected between February 2013 and February 2015. Individuals were measured, analyzed for sex and stage of reproductive development. In total, 1,564 individuals were analyzed in Anchieta, 534 males (74 juveniles and 460 adults) and 663 females (88 juveniles and 575 adults), and 367 individuals were not identified to sex or maturity. Significant differences were observed in shrimp abundance, with higher catches at the shallowest sampling point and associated with the type of substrate (silt+clay), while in the rainy season (September to March) and dry season (April to August) there were no significant differences. Despite this, greater abundances were found in the rainy season. The sex ratio was 0.80♂: 1♀. Carapace length ranged from 5.7 to 28.9 mm, with larger sizes recorded for females, as well as a larger size at first maturation than males, 12.86 and 11.60 mm respectively. All stages of development of the seabob shrimp were observed at the sampling points and periods, which represents a pattern of continuous reproduction and recruitment of the species in the area. Considering the sample size used, which is comparatively smaller than other studies, all estimates confirm current knowledge about the biology of the species and provide robust data on the seabob shrimp off the Anchieta coast, which are necessary for management and conservation. spp commonly Santo Brazil effort 201 2015 measured total 1564 1 564 1,56 53 74 (7 46 adults 66 88 (8 57 adults, , 36 maturity abundance silt+clay, siltclay silt+clay silt clay (silt+clay) September March April August this 0.80♂ 080 0 80 1♀ 5 7 5. 289 28 9 28. 1286 12 86 12.8 1160 11 60 11.6 respectively periods area used studies conservation 20 156 56 1,5 ( 4 6 8 3 (silt+clay 0.80 08 2 128 12. 116 11. 15 1, 0.8 0.

Abstract Two new species of Hyalella S.I. Smith, 1874 are described from state of Jalisco, Mexico. Hyalella marysolae sp. nov. can be identified by the presence of small projections or carinae on pleonites 1−2, with the first antenna being composed of 12 articles and the second antenna being composed of 15 articles. The first maxilla bearing 2−3 distal pappose setae, and the propodus in male first gnathopod is hammer-shaped. Conversely, in H. morronei sp. nov., dorsal projections or carinae are absent on pleonites 1−2, with the first antenna being composed of 10 articles and the second antenna of 14 articles. The first maxilla always bears two distal pappose setae, and the propodus in male first gnathopod is hatchet-shaped. Both species are distinguishable from other Hyalella species found in Mexico by the second antenna. In these two species, the second antenna is approximately half as long as the total body length, and the peduncle comprises 14 −15 articles; whereas, in other Mexican species, it is shorter and composed of maximum 12 articles. Here, we add two species to the four previously described in Mexico as it is necessary to increase the knowledge of the alpha taxonomy of this group of crustaceans and compensate for the biodiversity of the genus being underestimated. SI S I S.I Smith 187 Jalisco sp nov 1 2 1−2 23 3 2− setae hammershaped. hammershaped hammer shaped. shaped hammer-shaped Conversely H hatchetshaped. hatchetshaped hatchet hatchet-shaped length −1 whereas Here underestimated 18 1− −