Swimming Legs Research Articles

On some deep-sea Stenheliinae from the Gulf of California and the west coast of the Baja California Peninsula (Mexico): the genus Delavalia Brady, 1869 and proposal of Archaeohuysia gen. nov. and Diarthropodella gen. nov. (Copepoda: Harpacticoida: Miraciidae).

Several species belonging to the harpacticoid families Ameiridae Boeck, Ancorabolidae Sars, Argestidae Por, and Rhizothrichidae Por have been described so far as an ongoing long-term project on the diversity of deep-sea benthic harpacticoids collected from the Gulf of California and Mexican Pacific. Amongst the several harpacticoid taxa, the subfamily Stenheliinae Brady (Miraciidae Dana) showed to be one of the most important components to overall species richness in deep-sea sediments. Following the rejection of segmentation pattern of the first swimming leg as the only discriminant for subgeneric assignment of stenheliin taxa, four new species of Delavalia Brady, 1869 and two new genera, Archaeohuysia gen. nov. and Diarthropodella gen. nov. are proposed herein. The new Delavalia species belong to the longicaudata-group with close relatives in shallow-water habitats. The so far monotypic Archaeohuysia gen. nov. showed to be unique in the combination of the general structure of the first swimming leg and retention of the primitive complement of four setae on the second endopodal segment of the same leg. Diarthropodella gen. nov. is the only stenheliin taxon with a two-segmented exopod of the first swimming leg. Some comments are given on probable multiple colonization events of stenheliin taxa.

Deep sea without limitsfour new closely related species of Emertonia Wilson, 1932 (Copepoda: Harpacticoida: Paramesochridae) show characters with a world-wide distribution.

The large-scale dispersal of deep-sea harpacticoid copepods is an increasing focus for ecological studies. A fundamental prerequisite for monitoring and explaining their geographical distribution is precise descriptions of their morphology. Four new, closely related species of the family Paramesochridae (Copepoda, Harpacticoida) were found in the deep sea of the Pacific (San Diego Trough and off Chile), the Atlantic Ocean (Porcupine Abyssal Plain and Angola Basin), and the Atlantic and Indian Ocean sectors of the Southern Ocean (Weddell Sea and off Crozet Island). The discovery of Emertonia berndi sp. nov., E. hessleri sp. nov., E. ilse sp. nov., and E. serrata sp. nov. increases the number of known deep-sea species in this genus to ten. The new species are placed in Emertonia Wilson, 1932 because of their one-segmented endopods on the second and third swimming legs. The presence of a two-segmented endopod on the fourth swimming leg allocates them to the andeep-group within this genus. The four species can be distinguished from their congeners by the strongly serrated spines on the exopods of their swimming legs and an outwardly directed flexible seta on the exopod of the fifth leg. It is conveivable that these two specific characters evolved only once in the genus Emertonia. Their apparently cosmopolitan distribution covers thousands of kilometres and spans all major oceans. This biogeographical pattern may be explained by resuspension events followed by passive transport by benthic currents. Discrepancies in their dispersal ranges may be a result of changing geological and oceanographic boundaries.

Two new species of the problematic harpacticoid genus Itunella (Copepoda, Canthocamptidae)

Abstract 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.

A new species of Paralaophonte Lang 1948 (Harpacticoida: Laophontidae), with notes on the phylogeny of the genus and its relationships with Loureirophonte Jakobi 1953 using Bayesian inference.

Early studies during the 1990s supported a close relationship between the genera Paralaophonte and Loureirophonte. Subsequent studies carried out during the first decade of the 2000s suggested the monophyly of the latter and that it could be nested within Paralaophonte, rendering the latter paraphyletic. However, efforts to synonymize these two genera were hampered by the lack of phylogenetic analyses at the species level. Here we describe a new species of Paralaophonte from north-western Mexico, P. ullama sp. nov., and we formally synonymize Loureirophonte with Paralaophonte for which we propose two monophyletic subgenera, Pa. (Paralaophonte) and Pa. (Loureirophonte). The detection of the species most closely related to P. ullama sp. nov. is controversial. Our Bayesian analysis indicates that the new species might be related to Pa. (Pa.) gurneyi, and to Pa. (Pa.) ormieresi and Pa. (Pa.) septemarticulata, with which they form a larger clade supported by a very low Bayesian Posterior Probability value. However, the precise nature of the relationship between the new species and Pa. (Pa.) gurneyi is hampered by the gap in our knowledge of the armature formulae of the swimming legs of the latter, and by the lack of the male of the new species. On the other hand, the new species share several characters with Pa. (Pa.) problematica, Pa. (Pa.) pacificavicinum, Pa. (Pa.) pacificaemulator, and Pa. (Pa.) pacifica, with which it might be related. Our Bayesian analysis of forty-two morphological characters at the species level confirmed earlier suspicions about the relationships between Paralaophonte and Loureirophonte, the latter being nested within the former, and showed the monophyly of the Paralaophonte-Loureirophonte clade with high Bayesian Posterior Probability value, thus confirming the synonymy of these genera. The Paralaophonte-Loureirophonte clade is defined by the synapomorphic dimorphism in the second endopodal segment of the second swimming leg of the male. We did not detect any (aut)apomorphy for Pa. (Paralaophonte). Paralaophonte (Loureirophonte) is defined by the presence of one seta only on the second endopodal segment of the second swimming leg, and the one-segmented endopod of the fourth swimming leg.

Dizzy triathlete-evidence supporting vestibular etiology.

Dizziness during or after the swimming leg is a common complaint among triathletes. We hypothesized that the dizziness is caused by asymmetrical cooling of the vestibular organ. This caloric response is characterized by involuntary eye movements called nystagmus. Altogether, 125 triathletes completed an electronic questionnaire. Fifteen triathletes who had frequently experienced dizziness during the swimming leg agreed to take part in a cold water swimming test. The test comprised two cold water swimming legs, first without earplugs and then with earplugs to prevent a potential caloric response. Eye movements and possible nystagmus were recorded immediately after the swimming legs. A majority (87%, 109/125) of athletes had experienced dizziness during triathlon races or training. Of these, almost all (97%, 106/109) experienced it during or after swimming. Dizziness affected the triathlon performance in half of the athletes with dizziness (50%, 51/102). Fifteen athletes participated in a cold water swimming test. During the first leg (without earplugs), 11/15 athletes (73%) experienced dizziness. Of these, six had nystagmus (55%), four had uncertain nystagmus (36%), and one did not have nystagmus (9%). Only one of these athletes experienced dizziness during the second leg with earplugs. The prevalence of dizziness among triathletes is notable. A large part of the dizziness is likely to be caused by caloric reaction of the vestibular organ. We recommend earplug usage for triathletes suffering from dizziness during the swimming leg.

A Comparison Of Soft-shell Crab Production Methods: Autotomy, Herbal Extract and Natural Rearing

The world market demand for soft-shell crabs is increasing due to their delicate taste and ease of eating. However, the current production methods of soft-shell crabs (mutilation / limb autotomy) is either considered unethical or the waiting period for molting is too long. Thus, this research assessed the effect of mutilation (removal of all appendages except swimming legs), using herbal extract (Vitomolt TM ) as a stimulant for moulting, and without stimulation (control) on growth (body size and weight increment), molting period, molting percentage and survival. It was observed that mutilation method stimulated faster molting in crabs compared using herbal extracts and naturals, however, with a significantly lower increase in body size and weight. Molting rate was highest in crabs subjected to mutilation (92%), followed by those injected with than Vitomolt TM (73%) and control (52%). The survival rate of crabs subjected to Vitomolt TM was the highest (94.8%) compared to mutilation group (91.7%) and control (89.6%). Based on these results, mutilation is not recommended for soft-shell crab production due to their lower body size and weight increment (lesser profit for farmers). The use of herbal extract (Vitomolt TM ) has huge potential as a stimulant for molting in soft-shell crab production as its usage increased survival and molting rate in S. olivacea .

Anti-parasitic effects of quinine sulfate on the swimming crab parasite Mesanophrys sp.

Mesanophrys sp. is a newly discovered parasitic ciliate, which can cause the death of swimming crabs (Portunus trituberculatus) during the winter period. In this study, the anti-parasitic effects and toxicity of quinine sulfate on Mesanophrys sp. were investigated. In vitro results showed that Mesanophrys sp. mortality rates were 100% when treated with quinine sulfate at 21.0, 18.0, 12.0, 12.0, 12.0, 12.0, and 12.0 mg/L for 0.5, 1, 2, 4, 6, 12, and 24 h, respectively. The 0.5 h-LC50, 1 h-LC50, 2 h-LC50, and 24 h-LC50 of quinine sulfate against Mesanophrys sp. were 11.87, 10.38, 8.71, and 5.23 mg/L, respectively. With the increased concentration of quinine sulfate or the prolongation of the treatment time, the morphology and structure of Mesanophrys sp. changed significantly. The parasites became rounded, cilia were shed, nuclear chromatin agglomerated but then disappeared, the mitochondrial membrane deformed and the ridge structure partially collapsed, cell membranes ruptured and the cytoplasm leaked out. In an in vivo trial, by adding quinine sulfate (12 mg/L) to the culture water, the survival rate of artificially infected crabs was 86.67 ± 5.77%, which was not significantly different from the survival rate (90%) of the crab in the control group but was significantly higher than the infection group without drug exposure (3.33 ± 5.77%). The protection rate of the drug against disease was 83.34%. In the treatment test, a dose of quinine sulfate (12 mg/kg) was given three times as an injection into a swimming leg of a crab that had been experimentally infected. Injection resulted in an increase in the survival of infected crabs from 11.11 ± 9.62% (infection group without treatment) to 77.78 ± 9.62%. There was no statistical difference in survival between the latter group and the control group (94.44 ± 9.62%). Finally, the bathing and injection methods caused no apparent harm to the feeding and movement activities of P. trituberculatus.

Taxonomy of three species of the genus Spinoncaea (Copepoda, Oncaeidae) in the North Pacific Ocean with focus on morphological variability.

Three species of Spinoncaea Böttger-Schnack, 2003 are newly recorded in three locations of the equatorial and temperate Pacific Ocean collected by using a net of 60 μm mesh size. For all three species, morphological characters and patterns of ornamentation were analyzed in detail and illustrations of both sexes, also including form variants of the females, are provided. For the first time, information about the variability of various continuous (morphometric) characters are given, such as the spine lengths on the rami of the swimming legs or the proportions of urosomites. The complementary morphological descriptions of the Pacific specimens focus on similarities or modifications of characters as compared to earlier descriptions of these species from the type locality and various other localities. For S. ivlevi (Shmeleva, 1966), originally but insufficiently described from the Adriatic Sea, the Pacific material is similar in most aspects to the comprehensive redescription of the species from the Red Sea and from the type locality, except for a difference in the morphometry of the distal endopod segment on the antenna, which is discussed here. For S. tenuis Böttger-Schnack, 2003, and S. humesi Böttger-Schnack, 2003, the Pacific material mostly coincides with the characteristic features as described in the original account from the Red Sea. For all three species, differences and/or additions in ornamentation details were found in Pacific specimens (e.g., on the intercoxal sclerite of the first swimming leg or on the genital somite of the male) and females with aberrant morphology were detected. Genetic analyses based on 12S srRNA revealed for two species, S. ivlevi and S. humesi, little or no differences in genetic sequences between Pacific specimens and those recorded from the Mediterranean Sea, thus demonstrating that specimens from both locations are conspecific. For S. tenuis, for which no comparable genetic data are available, 12S srRNA amplification was unsuccessful as was the amplification of mitochondrial COI (barcoding) for all three species. The applicability of using COI amplification for barcoding of oncaeid copepods is discussed.

A new Entomolepididae genus and a new species of Spongiopsyllus Johnsson, 2000 (Copepoda, Siphonostomatoida) and their association with Aplysina Nardo, 1834 (Porifera, Demospongiae) in Todos-os-Santos Bay, Bahia, Brazil.

The Entomolepididae family is a small taxon with a very characteristic body morphology and is represented, in the Atlantic Ocean, by three genera and five species. A recent study in Todos-os-Santos Bay, in Bahia State, has revealed a new species of Spongiopsyllus and a new species and genus belonging to the Entomolepididae. The new species of Spongiopsyllus is found in association with the sponge Aplysina cauliformis (Carter, 1882) sampled at the Porto da Barra beach. It is distinguished from its congeners mainly by differences in the segmentation pattern of the antennule, endopod of antenna, and the setation of the maxillule, maxilla and maxilliped. The new genus and species from Parmulodinae Eiselt, 1959 is found in association with the sponge Aplysina solangeae Pinheiro, Hajdu Custódio, 2007, sampled at the Yacht Club Beach. The genus differs from others Parmulodinae mainly due to segmentation pattern of the antennule, endopod of antenna, maxilliped and swimming legs.

Chemosensitivity and role of swimming legs of mud crab, Scylla paramamosain, in feeding activity as determined by electrocardiographic and behavioural observations.

Swimming crabs have a characteristic fifth pair of legs that are flattened into paddles for swimming purposes. The dactyl of these legs bears a thick seta along its edge. The chemoreceptive and feeding properties of the seta are supported with scientific evidence; however, there is no available data on the sensitivity of the setae in portunid crabs. The underlying mechanisms of the chemo- and mechano-sensitivity of appendages and their involvement in feeding activities of the mud crab (Scylla paramamosain) were investigated using electrocardiography and behavioural assay, which focused on the responses of the mud crab to chemical and touch stimulus. Electrocardiography revealed the sensory properties of the appendages. The dactyls of swimming legs and the antennules were chemosensitive, but not mechanosensitive and vice versa for the antennae. However, the mouthparts, claws, and walking legs were chemo- and mechanosensitive. Only the chemosensitive appendages, including the swimming legs, were directly involved in feeding. The flattened dactyls of the swimming legs were more efficient than the pointed dactyls of the walking legs in detecting the food organism crawling on the substrate. The structural features enhanced the capacity of the crab in coming into contact with scattered food items. This study revealed that the swimming legs are important appendages for feeding in the mud crab.

Two new Canthocamptidae (Copepoda, Harpacticoida) from sponges of the Kara and Laptev Seas

We studied copepods washed off the sponges from two Arctic seas: the Kara and the Laptev. We found new species in families Miraciidae, Canthocamptidae Brady, 1880, Argestidae, and Ectinosomatidae. We describe two new species of the Canthocamptidae Brady, 1880. Heteropsyllus spongiophilus sp. nov. from the Kara Sea, differs from its congeners in the armament of the swimming legs and the maxilliped. Mesopsyllus glacialis sp. nov. from the Laptev Sea, can be distinguished by the legs armament, its sexual dimorphism and the 7-segmented female antennules.

A new representative of the genus Bryocyclops Kiefer, 1927 from a karst cave in north-eastern Thailand (Copepoda, Cyclopoida, Cyclopidae) and comments on the generic affinities

The seventh Thai species of Bryocyclops Kiefer, 1927 – Bryocyclops jayabhumisp. nov. – was found in a karst cave in the Chaiyaphum Province of north-eastern Thailand. The new species differs from all previously-known species by the absence of an inner seta on the proximal endopod of the first four swimming legs. Bryocyclops jayabhumisp. nov. is most similar to B. maholarnensis Watiroyram, Brancelj & Sanoamuang, 2015 – the monotypic species of Group VII, which was previously described from Thailand. However, the new species differs from B. maholarnensis by having the following characteristics: i) posterior margin of urosomites serrated; ii) anal operculum triangular with acute-tip; iii) P1–P4Enp-1 without an inner seta; iv) armature on the female P2–P3Enp-2 and P4Enp; v) a transformed spine on the male P3Enp-2. In this study, the generic affinity of the genus Bryocyclops Kiefer, 1927 is discussed and redefined, based on the available literature concerning its principle morphology to fill the present knowledge gap about the characteristics of the genus.

A new genus of Parastenocarididae Chappuis, 1940 (Copepoda: Harpacticoida) from the Amazonian Region, Brazil, with close affinity to Murunducaris Reid, 1994

Abstract Santaremicaris gen. nov. is proposed to accommodate Santaremicaris amazonensis sp. nov., a new species collected by Noodt from the hyporheic zone of the Amazonas River at Santarem, Brazil, and Parastenocaris santaremensis Noodt, 1963, which is redescribed and designated as the type species of the new genus. The new genus is recorded also from several localities of the Amazonian hydrographic basin. Santaremicaris gen. nov. is well supported by clear autapomorphies, e.g., 1) the absence of distal spinules on the endopod of the second swimming leg of the male, which is ornamented with strong outer spinules along the first 2/3 of the segment and armed with a long distal seta the insertion area of which covers almost the whole width of the segment; 2) the presence of a triangular, short and strongly sclerotized endopod on the fourth swimming leg of the male; and 3) the presence of a long and slim male fifth leg ending in a long distal spiniform process, with irregular margins, armed with only three setigerous elements on the outer margin, and reaching the middle of the subsequent urosomal segment or beyond it. The new genus is closely related to Murunducaris Reid, 1994, with males sharing conspicuous ornamentation on the inner margin of the first swimming leg basis, represented either by an enlarged spinule accompanied by minute accessory spinules or by a row of strong spinules. In addition, the males of both Murunducaris and Santaremicaris gen. nov. share an enlarged intercoxal sclerite with a median process on the fifth leg.

Diversification of true water bugs revealed by transcriptome‐based phylogenomics

AbstractTrue water bugs (Hemiptera: Heteroptera: Nepomorpha) are among the most common insects of freshwater ecosystems, comprising approximately 2300 extant species spread over five recognized superfamilies, including Corixoidea, Nepoidea, Ochteroidea, Notonectoidea and Naucoroidea. They exhibit striking morphological and behavioural adaptations to various freshwater environments, including oar‐like swimming legs, breathing siphons or plastron respiration. The phylogeny of Nepomorpha remains contentious, particularly for the early‐diverging lineage, which has hindered the understanding of the evolution of morphology and respiratory behaviour within the clade. In the present study, we assembled a large‐scale phylogenomic dataset, including 2018 single‐copy, protein‐coding gene sequences from 85 representative species of heteropterans (44 nepomorphans) to investigate the phylogeny of Nepomorpha and the corresponding implications for character evolution. Our inferences suggest that Corixoidea is the sister group of the remaining Nepomorpha, then Nepoidea and Ochteroidea; these clades successively branched in the Triassic, following the end‐Permian extinction event about 251 million years ago. The five superfamilies radiated in the Jurassic, when geological reconfigurations and drastic climate changes occurred. An ancestral state reconstruction demonstrated that the ancestral respiration type in true water bugs is likely a simple air‐bubble type, which was widely utilized in true water bugs. Subsequently, different clades have evolved variously specialized adaptations to improve its efficiency. We propose that the crawling legs of Nepidae are secondary or symplesiomorphic characters, which cannot serve as the evidence for the sister group role of Nepoidea to the remaining nepomorphans.

Quinquelaophonte enormis sp. nov., a new interstitial copepod (Harpacticoida: Laophontidae) from Korea.

We collected an undescribed laophontid copepod from a coarse sand habitat on the east coast of Korea and named it Quinquelaophonte enormis sp. nov. We compared the detailed morphological characteristics of the new species with those of congeneric species. Among them, the new species shows a superficial resemblance to the Californian species Quinquelaophonte longifurcata Lang, 1965. However, the two species are easily distinguishable by the setation of the syncoxa on the maxilliped and the fourth swimming leg. The new species has the variable setation on the second to fourth swimming legs. The variations appear among individuals or between the left and right rami of a pair of legs in a single specimen. Although complex chaetotaxical polymorphism occur in this new species, we used myCOI and Cytb to confirm that the new species is not a species complex. Also, partial sequences of 18S and 28S ribosomal RNA genes were used to analyze the position of the new species within the family Laophontidae. The new speciesis the fourteenth Quinquelaophonte species in the world and the second species in Korea.

Vorticella and Colacium as epibionts of copepods in Pasig river, Philippines

The chitinous exoskeleton of copepods serves as a scaffold for microepibionts such as protozoa. Although copepods are highly cosmopolitan, their associated epibionts in the tropics are poorly known. This study presents the first account in the Philippines of the ciliate Vorticella on calanoid copepod Arctodiaptomus dorsalis and both Vorticella and the euglenoid Colacium on the cyclopoid copepods Thermocyclops crassus and Mesocyclops microlasius in the Pasig River. Infestation, however, was low at 0.83% (108 out of 13,039) observed copepods from four collection sites in January-May and July-December 2018. Interestingly, Vorticella and Colacium were frequently observed in cyclopoid than on calanoid copepods, predominantly on the urosome, thorax, cephalosome of copepodites and adult stages of copepods. Colacium was also found attached on the antennules, swimming legs, caudal rami and setae. Prevalence of epibionts was site-related; Vorticella being more abundant in waters near Manila Bay (Site 1) where high salinity, conductivity and total dissolved solids were recorded while Colacium was found more near Laguna de Bay (Site 4). Both were abundantly present in September and absent in May, due to increased inflow of seawater from Manila Bay. Nevertheless, overall low infestation resulted in neither significant spatial nor temporal variation of epibiosis in Pasig River, probably due to heavy loadings of wastewater from nearby tributaries, noticeable algal blooms, detachment of epibionts by predations and changes in water chemistry.

Is limb autotomy really efficient compared to traditional rearing in soft-shell crab (Scylla olivacea) production?

There is currently a global high market demand for soft-shell crabs, which are priced much higher than crabs in hard-shell conditions. In order to harvest crabs in soft-shell conditions, they are reared and collected as soon as they molt, and limb autotomy is commonly used to hasten the molting process. In this study, we compared full limb autotomy (the removal of all the appendages except for the swimming legs), partial limb autotomy (the removal of the walking legs), and traditional rearing methods (control) using immature mud crab (Scylla olivacea) juveniles. The longest and shortest molt cycle duration was observed in the control group and the full limb autotomy group, respectively. The molting percentage was the highest in the full limb autotomy group (females) and in the partial and full limb autotomy groups (males; no significant difference between the groups). The survival rate was unaffected by limb autotomy. Post-molting, the carapace length (CL) and body weight (BW) increments of both sexes, and the carapace width (CW) increment of males were the highest in the control group. The average BW after molting was the highest in the control group, followed by the partial and then the full limb autotomy group. The average total harvest weight, however, was lowest in the control group, while no significant difference was observed between the limb autotomy treatments, owing to their low molting percentage and resulting weight gain per animal. Thus, although limb autotomy (partial or full) significantly shortened the duration of the molt cycle, it may not be as efficient as traditional rearing methods as it resulted in soft-shell crabs of lower aesthetic value (with missing limbs or uneven limb sizes), body size, and weight, all of which are important criteria for determining crab prices.

Restructuring the Ancorabolidae Sars (Copepoda, Harpacticoida) and Cletodidae T. Scott, with a new phylogenetic hypothesis regarding the relationships of the Laophontoidea T. Scott, Ancorabolidae and Cletodidae

Uncovering the systematics of CopepodaHarpacticoida, the second-most abundant component of the meiobenthos after Nematoda, is of major importance for any further research dedicated especially to ecological and biogeographical approaches. Based on the evolution of the podogennontan first swimming leg, a new phylogenetic concept of the Ancorabolidae Sars and Cletodidae T. Scott sensu Por (Copepoda, Harpacticoida) is presented, using morphological characteristics. It confirms the polyphyletic status of the Ancorabolidae and its subfamily Ancorabolinae Sars and the paraphyletic status of the subfamily Laophontodinae Lang. Moreover, it clarifies the phylogenetic relationships of the so far assigned members of the family. An exhaustive phylogenetic analysis was undertaken using 150 morphological characters, resulting in the establishment of a now well-justified monophylum Ancorabolidae. In that context, the Ancorabolus-lineage sensu Conroy-Dalton and Huys is elevated to sub-family rank. Furthermore, the membership of Ancorabolina George in a rearranged monophylum Laophontodinae is confirmed. Conversely, the Ceratonotus-group sensu Conroy-Dalton is transferred from the hitherto Ancorabolinae to the Cletodidae. Within these, the Ceratonotus-group and its hypothesised sister-group Cletodes Brady are combined to form a monophyletic subfamily Cletodinae T. Scott, subfam. nov. Consequently, it was necessary to restructure the Ancorabolidae, Ancorabolinae and Laophontodinae and extend the Cletodidae to include the displacement and exclusion of certain taxa. Moreover, comparison of the Ancorabolidae, Cletodidae, Laophontoidea and other Podogennonta shows that the Ancorabolidae and Cletodidae form sister-groups in a monophylum Cletodoidea Bowman and Abele, which similarly has a sister-group-relationship with the Laophontoidea T. Scott. According to the present study, both taxa constitute a derived monophylum within the Podogennonta Lang.

A new species of Tantulocarida (Crustacea) parasitic on a deep-water cumacean host from the southwestern Atlantic, with a review of tantulocaridan host utilization, distribution, and diversity

AbstractTantulocaridans (Class Tantulocarida) are primarily known to parasitize copepods, tanaidaceans, and isopods while only single species have been recorded from amphipod, ostracod, and cumacean hosts. Examination of a collection of deep-water peracarids from the Campos Basin off northeastern Brazil resulted in the discovery of a tantulus larva attached to a juvenile Styloptocuma angustatum (Jones, 1984) (Cumacea, Nannastacidae), representing a new species and only the fifth record for this host group. The new species is provisionally assigned to the genus AphotocentorHuys, 1991 (Cumoniscidae) based on the proximally dilated terminal caudal ramus setae, the conspicuous polygonal surface ornamentation on the thoracic somites, the spinous processes around the posterior border of the abdomen, the dorsal abdominal surface pattern consisting of four continuous transverse lamellae, and the spinular ornamentation on the protopods of legs 2–6. The tantulus of A. kolbasovisp. nov. is characterized by its large body size (175 μm), disproportionally long cephalic shield, the presence of paired papillae on the midventral surface of the cephalon, and the unique swimming leg setal formula, displaying the highest number of setation elements ever reported for leg 1. Except for the asymmetrically arranged median pores, the new species exhibits the full complement of cephalic pores, including the anterior pore AV. Current classification, known stages, tantulus body length, and distribution of all valid tantulocaridan species are presented. Literature records of Tantulocarida, including host group/species and depth, as well as those based exclusively on tantulus stages from the temporary meiobenthos or unidentified stages from the meroplankton are summarized. The authenticity of recently reported tantulus larvae on the lysianassid amphipod Lepidepecreella debroyeriSchiaparelli, Alvaro, Kilgallen, Scinto & Lörz, 2015 from Terra Nova Bay (Ross Sea, Antarctica) is scrutinized. Tumour-like anomalies on the exoskeleton of planktonic copepods in the central Red Sea and around hydrothermal vent fluids off Taiwan have erroneously been attributed to tantulocaridan infections.

CASE OF SHRIMP PLEOPOD NECROSIS IN TRADITIONAL PONDS THAT APPLY PROBIOTICS

Traditional ponds fail in vanname shrimp farming due to disease. Disease causing pathogens can come from the culture environment, innate from shrimp seeds, and other inputs (introduction). Observation of shrimp health condition through detection of necrosis in swimming legs which, if left unchecked, will spread to the shrimp abdominal carapace, with the characteristics of the shrimp will look flushed by taking shrimp samples, and the results are expressed in percentage or prevalence. Symptoms of loss of swimming legs and uropod from the disease, of course, will reduce the selling value of the shrimp. The study was conducted on a traditional pond in Banyuanyara Village, Sanrobone District, Takalar Regency, South Sulawesi Province. Early cases of necrosis began to be detected at week 5th and peaked at week 8th. Vanname shrimp swimming leg necrosis in traditional ponds is significantly influenced by the number of bacteria in the water, where the more bacteria there are, the lower the prevalence of vanname shrimp swimming leg necrosis.