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En el medio marino, las costas son reconocidas por su alta diversidad de especies, provocada por las variaciones naturales históricas y ecológicas que permiten la presencia de taxones de diferentes regiones. Sin embargo, la falta de información sobre la diversidad de ha sido un obstáculo para el desarrollo e implementación de estrategias, planes y metodologías de conservación. La bahía de Cispatá está ubicada en la zona litoral del Caribe colombiano, al costado suroccidental del golfo de Morrosquillo, específicamente en la región baja del delta del río Sinú, donde se localizan las formaciones más importantes de bosque de manglar del departamento de Córdoba, por la convergencia de dos grandes ecosistemas. El orden isópoda es uno de los grupos con mayor diversidad de los crustáceos y estos ocupan múltiples hábitats; desde marinos hasta continentales terrestres. Los isópodos juegan un rol ecológico importante en la cadena trófica como alimento y la desintegración de la materia orgánica. Se evaluó la diversidad y preferencia de microhábitat del orden en la bahía de Cispatá, de marzo a octubre del 2021. Para esto se realizaron cuatro muestreos en los meses de marzo (época seca), julio y junio (inicio de lluvias) y octubre (época lluviosa) en playa Nisperal, empleando metodologías de colecta para distintos microhábitats (hojarasca, raíces de manglar, algas y arena (playa)). Los resultados registraron la presencia de siete especies y una morfoespecie, con un total de 395 individuos. El microhábitat que tuvo mayor número de especies e individuos fue la arena (playa) con seis y 342 respectivamente, seguido por raíces de manglar con dos especies. En cambio, el microhábitat con menor número de especies y de individuos fueron hojarasca y algas. Por último, los resultados demostraron asociaciones entre los isópodos y los microhábitats en la bahía de Cispatá, siendo raíces de manglar y arena (playa) el microhábitat más utilizado frecuentemente. En este estudio se documentan 5 registros nuevos de isópodos para el Caribe colombiano: Natatolana gracilis, Littorophiloscia culebrae, Ligia (Megaligia) exótica, Exosphaeroma alba y Exosphaeroma diminutum, así como dos ampliaciones del ámbito geográfico para dos especies. 1. Introducción ........................................................................................................................... 10 2. Objetivos ................................................................................................................................ 13 2.1. Objetivo General ............................................................................................................ 13 2.2. Objetivos especifico ....................................................................................................... 13 3. Marco Referencial .................................................................................................................. 14 3.1. Antecedentes .................................................................................................................. 14 3.2. Marco teórico ................................................................................................................. 16 3.2.1. Historia de vida y breve definición del Orden Isopoda .............................................. 16 3.2.2. Morfología .................................................................................................................. 17 3.2.3. Clasificación taxonómica ........................................................................................... 20 3.2.4. Hábitat ........................................................................................................................ 20 3.2.5. Ecología de los isopodos ............................................................................................ 21 3.2.6. Impacto económico y ambiental de los isopodos ....................................................... 22 4. Diseño Metodológico ............................................................................................................. 24 4.1. Área de estudio ............................................................................................................... 24 4.2. Fase de campo ................................................................................................................ 25 4.3. Fase de laboratorio ......................................................................................................... 26 4.4. Análisis de la información .............................................................................................. 27 5. Resultados .............................................................................................................................. 28 5.1. Isópodos de la bahía de Cispatá ..................................................................................... 28 5.1.1. Natatolana gracilis Hansen, 1890 .............................................................................. 29 5.1.2. Excirolana sp.. ............................................................................................................ 30 5.1.3. Excirolana mayana Ives, 1891 ................................................................................... 31 5.1.4. Littorophiloscia culebrae Moore, 1901 ..................................................................... 32 5.1.5. Tylos niveus Budde-Lund, 1885 ................................................................................. 33 5.1.6. Ligia (Megaligia) exotica Roux, 1828 ....................................................................... 34 5.1.7. Exosphaeroma alba Menzies y Glynn, 1968 ............................................................. 35 5.1.8. Exosphaeroma diminutum Menzies y Frankenberg, 1966 ......................................... 36 5.2. Diversidad de especies ................................................................................................... 37 5.3. Isópodos por microhábitat y meses de muestreo ............................................................ 38 5.3.1. Preferencia de microhábitat de isópodos .................................................................... 38 5.3.2. Variabilidad temporal de las especies de isópodos .................................................... 39 5.4. Curvas de rango-abundancia .......................................................................................... 40 5.5. Índices de diversidad ...................................................................................................... 42 5.5.1. Índice de diversidad Shannon-Wiener (H´) ............................................................... 42 5.5.2. Dominancia de Simpson (λ) ....................................................................................... 42 5.5.3. Equidad o uniformidad de Pielou (J´) ........................................................................ 42 5.6. Curva de acumulación .................................................................................................... 43 5.7. Similitud entre especies y microhábitat: Dendograma (UPGMA) ................................. 44 5.7. Similitud entre especies y microhábitat: Dendograma (UPGMA) ................................. 44 7. Conclusiones .......................................................................................................................... 50 8. Recomendaciones ................................................................................................................... 51 9. Referencias Bibliográficas ..................................................................................................... 52 10. Anexos .................................................................................................................................... 58 Pregrado Biólogo(a) Trabajos de Investigación y/o Extensión

We compiled known occurrence records of seven species of crabs identified in the literature and one documented in this report as having undergone range extensions in southern Africa. Of these eight species, six (Austruca occidentalis, Neosarmatium africanum, Ocypode ceratophthalmus, Portunus segnis, Tubuca urvillei, and Varuna litterata) have extended their ranges either across a major biogeographic boundary that separates the subtropical and warm temperate ecoregions of this coast, or into estuaries that historically lack mangrove forests. For the seventh and eighth species, Charybdis smithii and Scylla serrata, we were unable to find any distributional data that supported poleward range extension. In addition, we contribute the first record of the blue swimming crab, P. segnis, from the temperate south coast of South Africa. This early detection is likely to be part of an ongoing regional trend of tropical-adapted brachyuran crab species extending their ranges into temperate ecoregions.

A new species of freshwater crab of the genus Teretamon Yeo & Ng, 2007, Teretamon husicum sp. nov., is described here from Husa Town, Longchuan County, Dehong Prefecture, Yunnan Province, China. Teretamon husicum sp. nov. can be distinguished from other species by a suite of morphological characters, including a bilobed frontal margin, smooth posterolateral regions, and a broadly rounded dorsal flap on the G1 terminal segment. An updated identification key for the species of the genus Teretamon is provided.

Naricolax holinorum sp. nov. is described based on specimens of both sexes recovered from the nasal cavity of Acanthopagrus schlegelii (Bleeker, 1854) (Pisces, Sparidae) in Japan. This species was erroneously redescribed first as N. atypicus Ho, Do & Kasahara, 1983 by Ho & Lin (2005) based on specimens of the female collected from the nasal cavity of A. schlegelii in Taiwan.

As in the original description of Naricolax sphyraenae Izawa, 2020, copepodid IV female of the species was described based on a wrong judgement of the sex, the species is redescribed and both sexes of copepodid IV of the species are correctively described, while additionally copepodid V male of the species is described for the first time, based on specimens newly collected from the original host, Sphyraena pinguis Günther, 1874 (Pisces, Sphyraenidae) from Japan.

The genus Itunella Brady, 1896 has a troubled taxonomic past, partly because of paucity of its members, but mostly because of inadequate research. A lack of detail in species descriptions and redescriptions, absence of alternative methods for testing species hypotheses, combined with a notion that most marine and estuarine animals have wide distributions and enormous intraspecific variability, all resulted in blurring of some interspecific boundaries, synonymizing without examination of the type material, and founding species diagnoses on dubious characters. Itunella yeondeokensis sp. nov. is described here in great detail from a small sandy beach on the east coast of Korea. It differs from all reported and illustrated congeners by an extremely long inner apical seta on the third exopodal segment of second to fourth swimming legs. This is the second member of this genus from Korea, the first one being described from three estuaries also on the east coast. All other congeners are European species. An overview of all published species and records of this genus is provided, as well as a dichotomous key to valid species to aid in their identification. Itunella kieferi sp. nov. is a new name for a single female from Germany, previously reported as a member of a widely distributed and polymorphic species.

In the present study, weight-at-age data of reared Pacific white shrimp, Penaeus vannamei Boone, 1931, were analysed under four different assumptions of variance (observed, constant, depensatory, and compensatory variance) in order to analyse the robustness for selecting the right standard deviation structure to parametrize the Von Bertalanffy, Logistic and Gompertz models. Selection of the best model and variance criteria were obtained based on the Bayesian information criterion (BIC). According to the results of the BIC, the observed variance in the present study proved to constitute the best way to parametrize the three above-listed growth models, and the Von Bertalanffy model appeared to be the best to represent the growth curve found. This is an asymptotic sigmoid curve with an inflection point. Based on these results, using the observed error structure to calculate the growth parameters in multi-model inference analyses is recommended.

This study was carried out to analyse the growth performance, feed utilization, and antioxidant capacity of juvenile mud crab (Scylla paramamosain) reared in two conditions. Here, a new indoor polypropylene tank culture system and a traditional outdoor pond cage facility were used to perform feeding experiments on juvenile crabs. After eight weeks, the survival rate, weight gain, moulting rate and feed efficiency of crabs cultured in polypropylene tanks were markedly higher than those cultured in pond cages. Moreover, the activities of serum acid phosphatase (ACP) and alkaline phosphatase (ALP), and the antioxidant indices including glutathione peroxidase (GSH-PX), glutathione transferase (GST), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) in hepatopancreas were higher in crabs cultured in the polypropylene tank system than those in pond cages. Based on these results, compared with the traditional pond cages, the polypropylene tank culture system is more suitable for the short-term culture of mud crabs.

This study searches to provide appropriate conditions to trigger spawning in Penaeus semisulcatus in aquaculture. The aim was to test the effect of 17β-oestradiol and 17α-hydroxyprogesterone on ovarian maturation and to study the correlation between the different stages of ovarian maturation and hormonal levels in the ovaries, hepatopancreas, and haemolymph. Female shrimps were collected from Ras El-Tin beach and the fishing port to Abu Qir Bay of the Mediterranean Sea off Alexandria, Egypt from June 2018-August 2019. Shrimps were individually weighed and subsequently killed by thermal shock at a maximum temperature of 45°C. Gonadosomatic and hepatosomatic indices were calculated. The correlation between the gonadosomatic and hepatosomatic indices indicates the presence of endogenous and exogenous vitellogenesis. The haemolymph, hepatopancreas, and ovaries were studied by stereo- and electron microscopy. From 15 females in each season the mentioned tissues were isolated for the extraction and quantification of steroid hormones during the different stages of gonadal maturation using radioimmunoassay. An ecdysteroid- and steroid-extraction protocol was applied. Aliquots were collected from the haemolymph to identify 17β-oestradiol and 17α-hydroxyprogesterone by mass spectrometry. Five stages of gonadal maturation were observed. The hepatopancreas was formed by a set of tubules lined with pseudostratified epithelium composed of five cell types, cell E (undifferentiated), cell F (fibrillar), cell B (vesicular), R (reabsorbing), and M (basal) cells. Steroidogenic tissues were small in size and numerous. The ultrastructure of the ovary and hepatopancreas were studied during oocyte development. There was a high concentration of 17β-oestradiol and 17α-hydroxyprogesterone in stages I and II of ovarian maturation, coinciding with the preparation phase for vitellogenesis. A progressive decrease of these steroid hormones occurred during the course of gonadal maturation, and reached its lowest concentration in the spawning period. The ecdysone concentration did not fluctuate in ripe females. Its level increases from stages I-IV of vitellogenesis onward.

In the last two hundred years, the Mureş River Floodplain has suffered major changes caused by dike constructions, meander cutting, and by the transformation of the natural landscape into an agricultural one. In this environmental context, we wanted to find out the degree to which large branchiopod species still survive in the Mureş Floodplain area. Every stagnant aquatic habitat encountered in 2019 in the Mureş Floodplain Natural Park was sampled. For the habitats where more species co-occur, urgent preservation actions must be taken. Most of the species prefer open habitats and have survived in the wheel ruts on agricultural lands. In the absence of natural habitats, the importance of this habitat type becomes a major one. The forest advantages species related to shady habitats, such as Chirocephalus diaphanus. We have found several individuals in the park that showed black spots on their bodies, characteristic of the black disease of fairy shrimp. The presence of the disease only in the populations from wheel ruts suggests that vehicles which make these ruts, could be the carriers of the disease.

This article uses the male spider crab Lissa chiragra, collected from Ras el Tin beach on the Mediterranean Sea at Alexandria, Egypt between January and December 2017, as a model to isolate the histone variants, H2A, H2B, H3 and H4 from spermatozoal nuclei to detect the presence of their genes and the chromatin-associated proteins. The spermatozoal chromatin in Brachyura is electron dense. During spermiogenesis somatic histones and sperm nuclear basic proteins (SNBP’s) are replaced partially or totally by protamines or keratin proteins, which are rich in arginine and oxidized cysteine. Histones, which are part of the nucleosome, are classified according to their functional and structural criteria into H2A, H2B, H3 and H4. Amino acids of the purified chromatin associated proteins are analysed with high resolution liquid chromatography. The low condensation of the nucleus of the spermatozoa is due to a low proportion and modification of the chromatin-associated histones. The DNA is organized into nucleosomes but not in higher order structures due to acetylation of histone H4, but rather via regions of histone-free DNA.

The male of an unknown species of Pennellidae is described based on a single specimen parasitic on the branchial lamellae of the limpid-wing flyingfish Cheilopogon unicolor (Valenciennes, 1847) (Pisces, Exocoetidae). The male has a 1-segmented abdomen and biramous legs 1 and 2, as well as uniramous legs 3 and 4; the rami of all legs are 2-segmented.

Female cleaner shrimps Lysmata amboinensis either underwent eyestalk ablations (EA), or were treated with two different wavelength intensities of red light (peak at 630 nm), and then their sex maturation and the effects on their egg quality parameters were compared. Vitellogenesis-inhibiting hormone (VIH), vitellogenin (VTG), VTG-receptor (VTG-R), and crustacean hyperglycemic hormone (CHH) expressions in the hepatopancreas were analysed. VTG-R expression (in situ) levels that caused the EA and red irradiation to induce the synthesis of VTG-R were assessed, and the triglycerides (TG) and glucose levels in the eggs were analysed. VIH expression was decreased in all experimental groups, but VTG and VTG-R expressions were increased. CHH expression and TG and glucose concentrations were higher in the red irradiation group, compared to the EA group. These results confirmed that the red light not only had a positive effect on the promotion of sex maturation, but it also improved the quality of the eggs, when compared to the EA method.

The spot prawn fishery, targeting Pandalus platyceros, has failed to prove commercially viable on the Mexican Pacific coast. A survey was carried out off the northwestern coast of Baja California, at depths of 140-180 m. The objective was to describe the biological traits of the species to test the hypothesis that warmer water stimulates higher growth parameters. An average model was estimated that anticipated an inverted exponential growth curve, consequently the growth parameters of the Von Bertalanffy model were obtained as , carapace length (CL) and . Being a protandric hermaphrodite, the transition size was estimated at 40.8 mm CL. The results challenged the hypothesis that P. platyceros grows faster in temperate environments than in cold environments.

In this study, we look at recent developments in our understanding of the life cycle of the red spiny lobster Panulirus argus (Latreille, 1804) and examine the evidence for connectivity between geographical regions, especially the north-northeast Brazilian continental shelf and the Wider Caribbean. The study also covers aspects of reproduction, phyllosoma density, large-scale oceanic circulation, self-recruitment, settlement patterns, ecological behaviour, and the impact of the Amazon and Orinoco river discharge on recruitment. Our findings support the hypothesis that lobster larvae are transported by ocean currents and free eddies from Brazil to the Caribbean via the Lesser Antilles, outlining a south-to-north connectivity. In addition, we look into the probable existence of hybrids between sympatric lobster species, as evidenced by differences in colour patterns and morphology.

The distribution of the semi-terrestrial burrowing crayfish Creaserinus fodiens (Cottle, 1863) in Ontario was updated based on the examination of the records stored in the crayfish database of the Royal Ontario Museum in Toronto and specimens collected during field studies. New Ontario locality records are reported for this crayfish species from MacGregor Point Provincial Park and other nearby sites in Bruce County, along the shores of Lake Huron. These are among the northernmost locality records reported for this species in North America. These new records represent a northwestern range expansion for this crayfish species in southern Ontario. As a result of these new records, the revised distribution of this species in Ontario is estimated to cover an area of about 32 620 km2. This is an increase of 7620 km2 over a previous 1996 estimate of this range. Creaserinus fodiens is a vulnerable species in Ontario, mainly due to the loss of suitable wetland habitats. Thus, the new locations and the range expansion reported here provide some hopeful news about the long-term future of burrowing crayfishes in this Canadian province. At some of the new locations, C. fodiens was found together with Faxonius immunis (Hagen, 1870), another burrowing crayfish species. However, this analysis of all the relevant records found in the collections of the Royal Ontario Museum (Toronto) and the Canadian Museum of Nature (Ottawa) shows that our knowledge of the distribution of C. fodiens in Ontario remains quite incomplete. A survey of the conservation status and challenges for this crayfish species in various regions of North America was also undertaken.

A new species of the thermosbaenacean genus Tethysbaena Wagner, 1994 (Crustacea: Peracarida: Thermosbaenacea) is described based on females from a freshwater cave lake and a brackish coastal well on Socotra Island (Yemen) as Tethysbaena dioscorida n. sp. It is the first representative of the Thermosbaenacea that is described from the Socotra Archipelago and the first member of the order known from an Indian Ocean island. The new species is the eighth known member of what is considered the “Tethysbaena relicta” species-group, which is known from Oman (four species), Somalia (one species), Israel (two species) and now Socotra Island (one species). The new species shows closest morphological affinities with T. barbatula Wagner, 2020 from Oman. We suggest that the speciation in this well-defined species-group is due to regressions of the Tethys Sea and the appearance of dry land since the Oligocene-Miocene boundary to the present time, forming major barriers and creating isolated populations of the ancestral species. Also the potential biocrisis in Socotra as a result of developmental activities during the last decades is mentioned, which may affect the subterranean faunas in particular in coastal areas, exemplified by the destruction of one of only two localities where the new species was found.

Orbitacolax bispinus sp. nov., Orbitacolax leptoscari (Yamaguti, 1953), Paraorbitacolax sphyraenae Izawa, 2021, and one male specimen of a Bomolochidae sp. are (re)described. The male and copepodid V female of O. leptoscari, and the male and copepodid V male of P. sphyraenae are described for the first time for the respective species. A description performed in Izawa (2020, 2021) that the maxilliped of the female bears a dorsal process in Orbitacolax and Paraorbitacolax spp., was wrong and is herein corrected.

Previous studies have revealed that reproductive traits of the Oriental river prawn Macrobrachium nipponense (De Haan, 1849) (Palaemonidae) can differ markedly across populations, though the environmental factors responsible for such variation are unknown. We therefore conducted monthly surveys of these prawns to determine their reproductive traits over two years at four study sites in southern Taiwan. The temperature, dissolved oxygen concentration, conductivity, and turbidity in Long Luan Lake significantly differed from the other sites, yet levels of reproductive trait parameters were intermediate among all. The aforementioned environmental factors were similar between the two Sihchong River sites and Mudan Reservoir, yet the river populations had the highest values in all reproductive traits. The river’s substratum was comprised of >60% of cobbles and boulders, whereas

A previous record of the alien crab Callinectes sapidus from the Algerian coasts was based on a photograph provided by a fisherman showing the dorsal side of a single individual. In this contribution, we confirm this presence in the mouth of the Mafragh Estuary in eastern Algeria, where four individuals of this species were found on 19 November 2019. The specimens examined are one female (60 mm CL, 125.9 g) and three males (60-66 mm CL, 120.4-176.8 g). This discovery confirms the presence of this species in the southwestern Mediterranean Basin where it could become invasive in suitable habitats.

The insulin signalling pathway is one of the most studied pathways, including ovary maturation and female reproduction. However, downstream elements involved in this cascade remain unknown. Here, we identified and characterized an insulin-like receptor (IR) in female Macrobrachium rosenbergii, and named as Mro-IR. The deduced Mro-IR contained conserved domains of IR proteins, including two ligand-binding domains, a furin-like domain, two fibronectin-3 domains, a transmembrane domain and an intracellular tyrosine kinase domain in order. Multiple sequence alignment of the first ligand-binding domain and the tyrosine kinase domain in Mro-IR revealed a high degree of similarity to other representative IRs. Mro-IR was clustered into a separate branch with IRs from decapods by phylogenetic analysis. Additionally, tissue distribution analysis showed that Mro-IR was uniquely expressed in the ovary of M. rosenbergii. This study would possibly provide a new highlight to the molecular mechanism of insulin-like signalling cascade, regulating female sexual differentiation in crustaceans.

The porcellanid crab Lissoporcellana demani Dong & Li, 2014 is reported for the first time from southeast Africa, based on material collected from trawls off Mozambique during the International Indian Ocean Expedition in 1963-1964. Lissoporcellana demani has been known only from the western Pacific, and the present specimens greatly extend the previously known distribution range of this species to the western Indian Ocean. Illustrations of a specimen are provided. Morphological variations of L. demani and characters distinguishing it from closely related congeneric species are discussed.

A new calanoid copepod, Sursamucro rostratus sp. nov., belonging to the family Aetideidae, is described from female specimens collected in the northern Pacific and South Atlantic from abyssal waters close to the sea bed. The new species is the second of a rare deep-water genus, Sursamucro; it differs from its congener in size, configuration of the rostrum, the shape of the posterior corners of the prosome and details of antenna, mandible, maxillule and P1 setation. The genus Sursamucro is recorded for the first time from the northern Pacific and the Atlantic Ocean.

Taeniacanthus aulacocephali sp. nov. recovered from Aulacocephalus temminckii Bleeker, 1855 (Serranidae) is described and T. sebastichthydis Yamaguti, 1939 collected from Sebastiscus marmoratus (Cuvier, 1829) and Sebastes inermis Cuvier, 1829 (Sebastidae) is redescribed. The male, copepodid V male, both sexes of copepodid IV, and copepodid II of the latter species are herein described for the first time.

Burrowing crayfishes have historically lacked life history data due to their elusive nature and difficultly extracting them from burrows. This review provides a synopsis of current literature on burrowing crayfishes’ life histories and a quantitative analysis of published life history content. Only 69 publications covering 94 burrowing species (approx. 39%) met our criteria for a life history study. Many species had only partial life histories documented and two genera (Engaewa and Tenuibranchiurus) had no life history studies available. Size and reproductive season were the most recorded traits across studies while others such as mortality and age/size at molting events were rarely recorded. Reproductive investment, an important predictor of imperilment, was lacking in 87% of burrowing species. Our review emphasizes the need to include life history data with new species descriptions and conduct basic life history studies to effectively assess data-deficient species and protect the future of our threatened burrowing crayfishes.

There are three major wild populations of mitten crab (Eriocheir sensu stricto), Suifenhe River (SF), Tumenjiang River (TM) and Liaohe River (LH) in northern China. However, the information on the nutritional quality of these three populations of crabs is still scarce. Thus, we investigated and compared the tissue indices, total edible yield, proximate composition, fatty acid compositions and amino acid contents of these wild crab populations. We showed that: (1) TM population had the highest meat yield among the three populations; (2) TM recorded the highest moisture and the lowest total lipid content in ovary and muscle; (3) a higher level of total n-3 poly-unsaturated fatty acids was found in TM, except for the ovary in SF; (4) the three populations had similar essential amino acids scores. In conclusion, Eriocheir s.s. from these three populations all showed a high nutritional quality suitable for humans, especially the TM, which contains more eicosapentaenoic acid and docosahexaenoic acid.

Two new species of Labidocera from Indonesian waters are herein described. Labidocera baliensis n. sp. is distinguishable in the female by the posterior corners of Pdg5 being rounded and equipped with a sub-posterior spine, the left side of Ur1 with a stout spine-like process, and the form of the P5; in the male by the Ur1 smooth and the very slender shape of P5. Labidocera gagensis n. sp. is distinguishable in the female by having 7 spine-like processes on Ur1, the structure of 6 spine-like processes on the posterior end of Ur2 and the form of P5; in the male by the long spine at the right posterior part of Ur1; and the 5 spine-like processes on the right posterior corner of Pdg5 as well as the form of P5. The relationships between the “detruncata” and “kroyeri” groups are discussed and defining characterizations of the species and of the species groups are provided.

The red swamp crayfish, Procambarus clarkii (Girard, 1852), is currently an economically important aquaculture animal. Its genetic basis has been scarcely reported, however, partly due to the absence of abundant molecular markers in the genome. In this study, Simple Sequence Repeat (SSR) loci were mined, based on genome survey sequencing via the next generation sequence of the red swamp crayfish. A total of 4897 SSR loci were identified, with the most abundant type being the di-nucleotide repeat motifs (75.2%), followed by tri- (20.4%), tetra- (3.8%), penta- (0.5%), and hexanucleotide (0.2%) repeats. In total, 1546 SSR markers were validated to be amplified, and 721 of these were identified as polymorphic SSR markers. Fifty polymorphic SSR markers were randomly selected for the identification of the genetic diversity of the 14 red swamp crayfish populations in China. The expected and observed heterozygosity and polymorphism information content were 0.39, 0.30, and 0.29, respectively, on average. The results indicated a medium genetic diversity among the 14 investigated populations. These probably cluster into three genetic populations. The current study provides abundant genetic markers and information on the 14 populations, which can be helpful for genetic diversity estimation and molecular breeding of the red swamp crayfish.

Two species of Euryplacidae were collected in western Mexico. Trizocarcinus dentatus (12 localities) and Euryplax polita (4 localities) were both found in the Gulf of California. In the case of E. polita 11 specimens (5 males, 5 females, one ovigerous female) were obtained, while in the case of T. dentatus 42 specimens (25 males, 10 females, 7 ovigerous females) were collected. The northern distribution limit of E. polita is extended to the northern Gulf of California (28°16′N 111°36′W). Environmental data for both species are provided, including depth range, temperature, dissolved oxygen, and sediment composition.

The sterol regulatory element-binding proteins (SREBPs) are a family of transcription factors known to activate the transcription of genes encoding key lipogenic enzymes. The present study reports on the molecular cloning, tissue expression and nutritional regulation of SREBP-1 from the swimming crab Portunus trituberculatus (Miers, 1876). The SREBP-1 full-length cDNA was 3785 bp, encoding a polypeptide of 1039 amino acids. Quantitative PCR analysis revealed that SREBP-1 expression was detected in various tissues, and the significantly higher expression levels were found in eyestalk and hepatopancreas compared with other tested tissues. Additionally, the effects of dietary iron on expression of SREBP-1 were investigated, and the results indicated that SREBP-1 expressions were down-regulated by crabs fed diets containing 218.9 and 373.9 mg/kg iron compared with that fed the basal diet (55.2 mg/kg). Suggesting that the relative expression level of SREBP-1 can be suppressed by dietary iron supplementation. These findings provide further insight into the regulatory capacity of SREBP-1 in the lipid anabolism of P. trituberculatus.

Adults of Portunus segnis were captured from Ras el Tin beach on the Mediterranean Sea at Alexandria, Egypt, from January to December 2017. Male crabs are present in higher density in the sea during fall and winter, while female crabs are more common during spring and summer. Sex ratios were calculated as follows: number of males or females/total number of crabs. The calculated sex ratios were subjected to a Chi-square test according to the equation: , where O represents the observed frequency and E the expected frequency. One-way analysis of variance shows differences in the carapace size (length and width) and the weight of males and females during the four seasons. The hepatosomatic index of male crabs ranges from 9.1-9.25 in winter months, 8.7-7.9 in fall, being lower, 3.12-2.25, in spring and 5.96-4.13 in summer. The hepatosomatic index of female crabs is 8.9-3.9 in spring, 9.2-7.9 in summer, shifts lower to 5.1-3.2 in fall and to 4.2-1.5 in winter. The gonadosomatic index of female crabs is 0.12-8.2 in spring, 0.20-13.9 in summer and decreases to 0.66-7.8 in fall and 0.18-4.7 in winter. Ovaries and testes were isolated, fixed, and prepared for histological examination. The testicular lobes are surrounded by simple epithelium with haemolymph filling the interspaces. Seminiferous ducts are inserted in the testicular lobes. Spermatogenesis and spermiogenesis are described. The vas deferens is usually filled with spermatophores. Spermatophore formation begins in the testis near the vas deferens. Near the base of the penes there is glandular tissue. This study proposes the classification of the ovarian maturation into five stages: Stage I, Immature ovary with primary and secondary oogonia; Stage II, early maturing ovary with germ cells in different maturation phases; Stage III, mature ovary with vitellogenic oocytes and germ cells; Stage IV, maturing ovary with oocytes I, II and fully mature oocytes; and Stage V, ovary in regeneration. The wall of the spermatheca consists of a stratified squamous epithelium.

Five species of Bomolochidae parasitic on Japanese fishes are (re)described. They are Orbitacolax leptoscari Yamaguti, 1953, Paraorbitacolax sphyraenae gen. et sp. nov., Pseudoeucanthus rhabdosargi sp. nov., Pumiliopes scombri sp. nov., and Triceracolax pagri gen. et sp. nov.

Prawns of the species Exopalaemon carinicauda were fed with Artemia that had been enriched by either 1, or 3, or 5 g/l DHA powder. The feeding dose of Artemia offered to E. carinicauda was calculated according to the water volume, and maintained at 1-3 individuals/ml. After nutritional enrichment, the ratio of DHA content to total fatty acid content in Artemia was the highest (3.32%) after being fed 3 g/l DHA powder. The ratio of DHA content to total fatty acid content in the muscle tissue of E. carinicauda prawns fed with Artemia enhanced with 3 g/l DHA powder was also the highest (4.40%) achieved. Furthermore, when the concentration of fish oil DHA powder was 3 g/l, the survival rate of the prawns was significantly higher than in the control group, with the specific growth rate and weight gain reaching 11.39%/day, and 95.74%, respectively. In addition, the DHA-enhanced Artemia, at different concentrations, increased the non-specific immunity of individuals. The enzyme activity of T-AOC, SOD and AKP in the respective feeding groups of prawns was significantly higher, compared to the control group. Thus, Artemia enriched by 3 g/l DHA powder is proposed as an optimal choice for the offspring breeding of E. carinicauda.

The migratory behavior of females of the freshwater prawn Macrobrachium amazonicum (Heller, 1862) can indicate a strategy that optimizes the population establishment. With this idea in mind, we evaluated the reproductive biology of M. amazonicum, hypothesizing that females were evenly distributed downstream of Hydroelectric Dam. Specimens were collected monthly for one year, from six sites of Rio Grande river. The specimens were sexed and measured (carapace length; CL). A total of 14,697 adults were captured, 2,864 males (AM), 11,082 non-breeding females (AF) and 751 breeding females (BF). The smallest BF had 3.8 mm CL. The distribution of demographic groups was assessed by a Principal Component Analysis (PCA), which explained 95.16% of the distribution over the collection sites. Breeding females were more abundant in the sites closest to the dam. This result can be explained by rainfall, which varied significantly throughout the year. As the breeding females migrated upstream toward the dam and were more abundant there, our hypothesis of homogeneous distribution was rejected. This behavior probably optimizes larval dispersion. The reproduction was continuous with peaks in the period preceding the maximum rainfall.