Multidisciplinary approach to the diagnosis of Contracaecum magnipapillatum infections in Australian black noddies, Anous minutus (Charadriiformes: Laridae).

We provide the incidental necropsy findings associated with anisakid nematode infections of black noddy terns, Anous minutus Boie, 1844 (Charadriiformes: Laridae), from offshore islands in the southern Great Barrier Reef, Queensland, Australia. Specimens collected from the proventriculi were identified morphologically as Contracaecum magnipapillatum Chapin, 1925 (Rhabditida: Anisakidae), using light and scanning electron microscopy (SEM). The entire nuclear ribosomal DNA internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2) was amplified by polymerase chain reaction (PCR) and sequenced to provide reference sequences for morphologically well-identified voucher specimens. Interestingly, after an alignment with closely related taxa using BLAST, sequences of the ITS1 and ITS2 were 100% identical to the sequences assigned to Contracaecum septentrionale Kreis, 1955, from a razorbill, Alca torda Linnaeus, 1758 (Charadriiformes: Alcidae), from Spain. These results either raise questions about the ITS as a genetic marker for some members of Contracaecum, or the identity of the specimens assigned to C. septentrionale, given that no supporting morphological data was associated with them. We highlight the need for a combined morphological and molecular approach to parasite diagnostics and the use of multiple genetic loci to resolve the molecular taxonomy of cryptic species. Morphological identifications should be taxonomically robust, transparent and precede the deposition of molecular barcodes in public repositories. The gross and histopathological findings of our investigation concur with previous reports of widespread Contracaecum infections in black noddies and support the contention that Contracaecum spp. are an unlikely primary cause of mortality.

High-quality DNA isolation protocol for detection of Khapra beetle (Dermestidae: Trogoderma granarium Everts, 1898) in standard wheat germ trap.

BACKGROUND: Khapra beetle (Dermestidae: Trogoderma granarium Everts, 1898) is an internationally significant pest of grain crops and stored grain products. Wheat germ traps, routinely used in surveillance sampling of Khapra beetle provide feed-substrates used by the pest throughout its life cycle. However, Khapra beetle larvae, eggs and other traces of the pest, such as larval frass and exuviae, in wheat germ traps are difficult to sort and taxonomically identify. Additionally, high levels of polysaccharides in wheat germ can inhibit PCR based molecular detection of this pest captured in the traps. METHODS AND RESULTS: We have developed a sensitive and low-cost protocol for extracting trace levels of Khapra beetle DNA from an entire wheat germ trap. Overnight digestion of entire trap contents in 6 mL of ATL buffer, followed by a 40 min lysis step was optimal for DNA extraction. Paired with reported qPCR assays, this protocol allows the detection of a few hairs of T. granarium in a typical 2-gram wheat germ trap. CONCLUSION: This DNA extraction protocol makes it possible to perform a more rapid identification of the pest following wheat germ sample collection. The protocol has potential to improve international efforts for Khapra beetle surveillance.

The effect of bariatric surgery on the expression of Growth Differentiation Factor-15/Macrophage-Inhibitory Cytokine-1 (GDF-15/MIC-1) in rat.

BACKGROUND: Reduced appetite and loss of preference to nutrition dense high-fat diet are present after bariatric surgery. But the mechanism responsible for these changes in biological activities remains unclear. Similar changes in biological activities have been observed with growth/differentiation factor-15/macrophage-inhibitory cytokine-1 (GDF-15/MIC-1) treatment alone. AIM OF STUDY: To assess the effect of bariatric surgery on GDF-15/MIC-1expression and circulating level in rodent model. SETTING: The Affiliated Hospital of Xuzhou Medical University, Xuzhou Jiangsu 221,006, P. R. China. METHODS: Among 40 fatty Sprague-dawley (SD) rats, 30 randomly receive low-dose STZ to induced diabetes and were randomly assigned to Roux en Y gastric bypass (RYGB, n = 10), Sleeve gastrectomy (SG, n = 10), and SHAM (n = 10). The remaining fatty SD rats were assigned to Normal control (NC, n = 10). Rats were followed for 8 weeks postoperatively. Circulating levels of GDF15 and tissue (gastrointestinal and liver) expression were assessed after surgery. Preoperative oral glucose tolerance test (OGTT), and Insulin tolerance test (ITT) were reassessed postoperatively. Changes in bodyweight and food intake were also recorded. RESULTS: Bariatric surgery significantly increased circulating plasma level of GDF15 (p < 0.05). Postoperatively, tissue expression of GDF15 was significantly higher in the stomach pouch, jejunum, and ileum of rats in the RYGB group as well as ileum of rats in the SG group compared to Sham and NC (p < 0.05). Higher Expression of GDF15 in the stomach pouch of the SG group was not statistically significant compared to the stomach of Sham and NC group. GDF15 expression in the liver was significantly less in the RYGB group (p < 0.05). CONCLUSION: Bariatric surgery significantly increases circulating levels and gastrointestinal tissue expression of GDF15. Given that GDF15 is an important regulator of energy homeostasis, further studies are needed to ascertain the relevance in bariatric surgery.

Phylogenetic relationships of philometrid nematodes (Philometridae Baylis & Daubney, 1926) inferred from 18S rRNA, with molecular characterisation of recently described species.

Nematodes of the family Philometridae Baylis & Daubney, 1926 (Dracunculoidea Stiles, 1907) are generally poorly known, and there are many taxonomic issues within the family. Philometrids are parasites of fish and are found in various locations throughout the host, including within the subcutaneous tissues and musculature, the abdominal cavity and gonads; vast sexual dimorphism often means the males are not collected, leading to many species being described solely on female characteristics. Although there have been a number of studies utilising molecular data, the vast majority of species are yet to be sequenced. This study undertook genetic sequencing of 15 recently described species of philometrids across 4 genera, many of which were from specimens collected from waters off Australia. All of the sequences obtained were closely related with representatives of the family Philometridae. Species were found to be distributed in the phylogenetic trees within 4 clades based on a combination of site of infection within the host and host habitat. Family of host and geographical location was not as important for position within the trees. Clade A contained philometrids collected from the abdominal cavities and head tissues of South American freshwater fish. Clade B contained philometrids primarily from the abdominal cavities of freshwater European cyprinids. Clade C contained philometrids primarily from the ovaries of marine fish. Clade D contained philometrids from the body tissues of marine and freshwater fish. The potential co-evolutionary patterns between philometrids and their fish hosts are highlighted as an area of future research. This research also highlighted the importance of correct identification of any sequenced specimen.

Characterization of tongue worms, Linguatula spp. (Pentastomida) in Romania, with the first record of an unknown adult Linguatula from roe deer (Capreolus capreolus Linnaeus).

Specimens of the pentastomid parasite, Linguatula serrata, have been reported from several animals in Romania, including some domestic dogs translocated to other parts of Europe. In this study, gray wolves (Canis lupus, n = 80), golden jackals (C. aureus, n = 115), red foxes (Vulpes vulpes, n = 236), and roe deer (Capreolus capreolus, n = 1) were examined for pentastomes. Overall, 17.5% of wolves were found to be infected with specimens of Linguatula, with a range of infections of one to five individuals per animal. Golden jackals and foxes had much lower infection levels, with 1.73% of golden jackals and 1.69% of foxes infected; both host species were found to be infected with one or two individual pentastomes per animal. The single deer specimen was infected with three individual pentastomes. The pentastomes collected from the wolves and golden jackals were determined to be immature and mature adult specimens of L. serrata based on morphological examination and molecular analysis using the 18S rRNA gene. No pentastomes collected from the red foxes were available for identification. The pentastomes collected from the roe deer were expected to be L. arctica but determined to be mature adult male specimens of an unknown Linguatula, herein, referred to as Linguatula sp. based on its morphology; the results of molecular sequencing for the Linguatula specimen collected from the deer were inconclusive, preventing a final species identification. This study presents the first report of L. serrata in any hosts from Romania through both morphological and molecular characterization, and also presents the first report of a Linguatula sp. in Ca. capreolus, utilizing morphological characterization. Issues of morphological variability are discussed, including the presence of spines in the hook pit of specimens of Linguatula. This study highlights the need to examine all specimens of Linguatula to confirm the stage of development. Despite the inconclusive molecular result for some specimens, the authors still urge future researchers to incorporate a combined molecular and morphological approach in identifying specimens of Linguatula.

28S rRNA sequences for Linguatula spp.

Identification of specimens belonging to the genus Linguatula (Pentastomida) is relatively easy due to their unique morphology. However, differentiation between species of Linguatula can be challenging for several reasons, including considerable differences between different developmental stages of the parasite within and between species. Currently, 18S rRNA and Cox1 sequences are the only available comparable sequences in GenBank, but recent research has discussed the utility of 28S rRNA for pentastomid phylogenetics. This study presents 28S rRNA gene sequences for two members of the genus Linguatula. Sequences of 28S rRNA were successfully obtained from well-identified samples of L. serrata (collected in Australia) and L. nuttalli (collected in South Africa), with voucher specimens. Phylogenetic analysis of the 28S rRNA region showed 6% difference between L. serrata and L. nuttalli, with low levels of intraspecific variation. In comparison, 18S rRNA and Cox1 sequences from the same specimens showed 0.23% and 13% interspecific differences, respectively. The results of this study show that 28S rRNA has greater genetic diversity to allow for improved differentiation between species of Linguatula than 18S rRNA but is on par with Cox1. Records that do not provide adequate morphological or molecular data to justify independent specific diagnoses must be regarded cautiously, and the need for continued research on species of Linguatula, using a combined morphological and molecular analysis, across a number of different hosts, development stages, geographical regions and molecular markers is highlighted.

Dolichoperoides macalpini (Nicoll, 1914) (Digenea: Dolichoperoididae) infecting venomous snakes (Elapidae) across Australia: molecular characterisation and infection parameters.

Specimens of Dolichoperoides macalpini (Nicoll, 1914) (Digenea: Dolichoperoididae) were collected from Australian venomous snakes (Elapidae): Notechis scutatus Peters, 1861 and Austrelaps superbus (Günther, 1858) from Tasmania and surrounding islands and N. s. occidentalis Glauert, 1948 from wetlands near Perth, Western Australia. Despite variation in morphological measurements, genetic analysis showed that the one species of digeneans infected the snakes from all locations. This study presents the first DNA sequences for D. macalpini (internal transcribed spacer, 18S, 28S), confirming its placement in a family separate from the Reniferidae and Telorchiidae. Analysis of the infection dynamics of infection in Western Australian snakes showed significant differences in levels of infection between wetland locations, season and year of collection. Infection of D. macalpini was reported in the gastrointestinal tract, including the mouth, in freshly euthanised snakes in Western Australia, and in the lung in Tasmanian snakes, consistent with earlier reports. Differences in morphology and site of infection are suggested to be due to a combination of season and maturity of the digenean, with infection potentially occurring early in the season, as the snakes emerge from torpor. The need for research on the seasonal dynamics of infection with this parasite is discussed.

Two new parasitic copepods of the family Sphyriidae (Copepoda: Siphonostomatoida) from Australian elasmobranchs.

Two new species of the genus Tripaphylus Richiardi in Anonymous, 1878 (family Sphyriidae) are described from elasmobranch hosts caught as bycatch within the Demersal and Timor Reef Fisheries which operate in the Northern Territory exclusive economic zone. Tripaphylus squidwardi n. sp. was collected from Carcharhinus coatesi Whitley and had a prevalence of 11.6%. Tripaphylus dippenaarae n. sp. was collected from Rhizoprionodon acutus (Rüppell) and had a prevalence of 28.2%. The new species are distinguished from existing congeneric species by the body proportions and shape of the adult female and by the arrangement of lobes on the ventral surface of the cephalothorax.

Diagnosis and genetic analysis of a case with glycogen storage disease type V caused by compound heterozygous mutations in the PYGM gene.

Glycogen storage disease type V is an autosomal recessive genetic disorder caused by muscle glycogen phosphorylase (PYGM) deficiency, which is characterized by exercise intolerance, second wind phenomena and high level of serum creatine kinase. In this study, we reported a Chinese young man with glycogen storage disease type V, with lower extremity weakness after exercise, increased creatine kinase, and slight fat infiltration in the posterior group of thigh muscle by magnetic resonance imaging (MRI). The proband had complex heterozygous PYGM disease-causing mutations, including c.308T>C (p.L103P) variant transmitted from the mother and c.260_261delCT (p.S87Ffs*23) from the father, of which the former was a novel PYGM mutation. This study enriched the PYGM pathogenic gene mutation spectrum, contributed to improve clinicians' understanding of glycogen storage disease type V and provided a reference for further genetic study of the disease.

Safety of peripheral gastric vessel coagulation during laparoscopic sleeve gastrectomy.

INTRODUCTION: Staple-line bleeding (SLB) is a common issue during laparoscopic sleeve gastrectomy (SG). Identifying a method or technique intraoperatively to manage or reduce the prevalence of SLB is crucial. MATERIALS AND METHODS: Patients' data who had undergone primary laparoscopic SG from January 2018 to December 2019 at our hospital were retrospectively analysed. The patients in this study received peripheral gastric vessel coagulation intervention in addition to the standard SG procedure. Preoperative parameters included age, gender, body mass index (BMI), the prevalence of diabetes and hypertension. Intra- and postoperative parameters were prevalence of SLB, operative time, total postoperative stay, the prevalence of leakage and bleeding. Intraoperative SLB was identified and analysed through video recordings. RESULTS: 217 cases of laparoscopic SG were included in the study. The mean preoperative assessments were as follows: age, 34.2 ± 10.7 years; male/female, 98/119; BMI, 39.9 ± 7.6 kg/m2; prevalence of diabetes, 52 (24.0%) and hypertension, 90 (41.5%). Of 217 patients, 35 (16%) were found to have SLB following the new interventional procedure. The mean operative time was 93.2 ± 13.6 min. The mean total postoperative stay was 3.3 ± 1.3 days. The postoperative prevalence of leakage and bleeding were 0% and 0%, respectively. CONCLUSION: The technique of coagulating the peripheral gastric vessels to prevent SLB is safe and appears promising. A prospective study comparing with and without peripheral gastric vessel coagulation will be needed in the future.

The taxonomic position of Anoplotaenia dasyuri (Cestoda) as inferred from molecular sequences.

Anoplotaenia dasyuri Beddard, 1911 (Cestoda), from the Tasmanian devil, Sarcophilus harrisii (Boitard, 1842), is a taxonomic enigma, where a combination of morphological features, host type and geographical location have prevented it from being placed within a family and it is considered incertae sedis, despite its accepted validity. We performed a phylogenetic analysis of three A. dasyuri specimens collected from three Tasmanian devils using 18S and 28S rRNA sequences. Anoplotaenia dasyuri was found to have closest affinity with the family Paruterinidae, especially the genus Cladotaenia Cohn, 1901. The postulated theory of transfer of an ancestor of Anoplotaenia Beddard, 1911 transferring to the Tasmanian devil from an unrelated carnivorous host, such as an accipitriform or other carnivorous bird, is discussed and supported.

Characterization of Clinostomum sp. (Trematoda: Clinostomidae) infecting cormorants in south-eastern Australia.

Clinostomum Leidy, 1856 (Trematoda: Clinostomidae) is a cosmopolitan, zoonotic genus of fluke that has been poorly studied in an Australian setting. Following previous reports of reservoir fish in Australian fish ponds being heavily infected with Clinostomum metacercaria, the current study was conducted to determine the specific identity of Clinostomum sp. in inland Australia, by examining and characterizing parasites collected from a potential definitive host, cormorants. A total of 33 parasite specimens belonging to the genus Clinostomum were collected from two cormorants (little black cormorants, Phalacrocorax sulcirostris) that were collected from the Narrandera Fisheries Research Centre, New South Wales, at the same locality where metacercaria of Clinostomum sp. have been reported in fish. All specimens in our study were immature adults. Clinostomum specimens with similar morphology have been identified as C. complanatum in the past, based on their morphological characteristics. However, phylogenetic analyses based on the ITS sequence data in the present study suggest they are the same as the Clinostomum sp. previously reported from carp gudgeons (Hypseleotris spp.) from the same farm, and distinct from C. complanatum. The ITS sequences obtained from the specimens in the present study were most similar to those belonging to C. phalacrocoracis (never reported in Australia). Our specimens formed a distinct clade on the phylogenetic tree and their specific identity awaits until fully mature specimens are described in future studies.

Infection of Hexametra angusticaecoides Chabaud & Brygoo, 1960 (Nematoda: Ascarididae) in a population of captive crested geckoes, Correlophus ciliatus Guichenot (Reptilia: Diplodactylidae).

Here we report on the infection of captive crested geckos Correlophus ciliatus Guichenot (Reptilia: Diplodactylidae), with adults of the ascaridoid nematode, Hexametra angusticaecoides Chabaud & Brygoo, 1960 (Ascarididae). A population of captive crested geckoes became ill and died within a short period of time. Nematodes were recovered from the crested geckoes examined from within the coelomic cavity, penetrating various organs and migrating through subcutaneous tissues, as well as emerging through the geckos' skin. One gecko was treated with levamisole following surgical excision of nematodes from under the skin; this gecko survived. The potential source of the nematode infection in the captive geckoes is discussed. It is most likely that wild-caught Madagascan mossy geckoes, Uroplatus sikorae Boettger (Reptilia: Gekkonidae), introduced the infection to the colony. Molecular sequences of the nematodes are the first produced for the members of this genus. A redescription of the species and its genetic characterization based on the internal transcribed spacer sequence data is provided, suggesting some of the morphological criteria that have been used in the past to distinguish between Hexametra spp. may have been intraspecific morphological variations.

Distal gastric mucosa ablation induces significant weight loss and improved glycemic control in type 2 diabetes Sprague-Dawley rat model.

BACKGROUND: Excluding the foregut (distal stomach and duodenum) from food transit in RYGB normalizes glucose tolerance. Excluding/removing the duodenal mucosa partly improves glycemic control. So far, the effect of excluding/removing the gastric mucosa remains unknown. OBJECTIVE: To observe the effect of removing the distal gastric mucosa on glucose tolerance. METHOD: Thirty fatty Sprague-Dawley rats received low-dose streptozotocin (STZ) to induce type 2 diabetes (T2D), then randomly assigned to Roux-en-Y gastric bypass (RYGB, n = 8), distal gastric mucosa removal (DGMR, n = 8), duodenal-jejunal bypass (DJB, n = 8), and Sham (n = 6) groups. In the DGMR group, the distal third of the gastric mucosa was removed by thermal ablation using an electrocautery. Rats were followed for 8 weeks postoperatively. Preoperative oral glucose tolerance test (OGTT), insulin tolerance test (ITT), and mixed-meal tolerance test (MMTT) were repeated 3 and 6 weeks postoperatively. Changes in body weight, food intake, and fasting blood glucose were also recorded. RESULTS: Gastrin AUC decreased significantly (p < 0.05) in the DGMR group after surgery. A significantly increased GLP-1 AUC was found in the RYGB, DGMR, and DJB groups at week 3 and only the RYGB group at week 6 postoperatively. The improved glucose tolerance in the RYGB group was significantly greater than the improved glucose tolerance in the DGMR and DJB groups. The improved glucose tolerance 3 and 6 weeks after surgery in the DGMR group was significantly greater than the improved glucose tolerance in the DJB group. Body weight decreased significantly in the RYGB, DGMR, and DJB groups postoperatively. CONCLUSION: Removing the distal gastric mucosa induced significant weight loss and improved glycemic control in T2D SD rat model. Therefore, the gastric mucosa exclusion in RYGB may be key to the weight loss and diabetes remission, which perhaps warrants a new theory.

Intermittent Splenic Artery Occlusion Plus Gauze Compression Is a Simple and Effective Treatment for Iatrogenic Splenic Injury.

BACKGROUND The aim of this study was to evaluate the feasibility and safety of intermittent splenic artery occlusion plus gauze compression in treating iatrogenic splenic injury. MATERIAL AND METHODS We retrospectively analyzed 12 iatrogenic splenic injury cases (grade I to III) treated with intermittent splenic artery occlusion plus gauze compression. The hemostatic effect was then observed after unblocking and decompression. The total operation time, gauze compression time, total blood loss, blood loss from the injured spleen, and platelet counts of each patient before and 1 week after surgery were noted. RESULTS The average operation time was 209.58±57.11 min, and the average gauze compression time after spleen artery occlusion was 23.75±4.33 min. The average total blood loss and blood loss due to iatrogenic spleen injury were 468.33±138.22 ml and 264.17±165.72 ml, respectively. Two cases (both grade I) had successful hemostasis after 15 min of splenic artery occlusion and wound compression. Another 9 cases (all grade II) and 1 case (grade III) attained hemostasis after 25 min and 30 min, respectively, of splenic artery occlusion and wound compression. The platelet counts of all patients were within the normal range before and 1 week after surgery. No postoperative complications occurred. CONCLUSIONS Intermittent splenic artery occlusion plus gauze compression is a simple and effective treatment for iatrogenic splenic injury.

Description and genetic characterisation of Pulchrascaris australis n. sp. in the scalloped hammerhead shark, Sphyrna lewini (Griffin & Smith) in Australian waters.

Being listed in the IUCN Red List of Threatened Species, knowledge on the biology, health and diseases of the scalloped hammerhead, Sphyrna lewini (Griffith & Smith) is limited; this is especially true for its parasites. In this paper, a new species, Pulchrascaris australis, is morphologically described followed by genetic characterisation based on the sequence of the ITS region. The new species can be easily differentiated from its congeners based on the morphology of the mouthpart, spicules, plectanes, eggs and vulva. Phylogenetic analyses clearly distinguish specimens in the present study from other parasitic nematodes found in the Australasian waters and elsewhere. The sequencing data also suggest that Terranova larval type I found previously in various fish from New Caledonian and Australian (Queensland) waters also belong to Pulchrascaris australis n. sp.

Verification of rabbits as intermediate hosts for Linguatula serrata (Pentastomida) in Australia.

We confirm the presence of nymphs of the introduced pentastomid, Linguatula serrata, in the introduced rabbit, Oryctolagus cuniculus, in Australia, based on morphological and molecular results. Two nymphs were collected from a single rabbit near the Kosciuszko National Park in New South Wales. Unlike reports of nymphs from domestic animals, these nymphs were not encapsulated, despite having the morphological features of infective nymphs. The possibility of different development pathways in lagomorphs is discussed. Examination of feral deer for L. serrata was unsuccessful and potential reasons for a lack of infection in these animals are postulated. Our results reiterate the need for a combined morphological and molecular approach to the identification of L. serrata. Further sampling of a range of feral and native animals is required to determine the true range of intermediate hosts and their relative importance in the transmission of L. serrata in Australia.

Absorbable suture can be effectively and safely used to close the mesenteric defect in a gastric bypass Sprague-Dawley rat model.

BACKGROUND: To observe if closing the mesenteric defect with absorbable sutures creates a safe adhesion compared to non-absorbable suture after Roux-en-Y gastric bypass. METHODS: Rats were randomly assigned to 5 experimental groups according to the different suture materials used in closing the mesenteric defects (Peterson's space) after Roux-en-Y gastric bypass. Group A (control group), Group B (non-absorbable suture, Prolene suture), Group C (biological glue), Group D (non-absorbable suture, polyester suture) and Group E (absorbable suture). All rats were followed up for 8 weeks postoperatively and underwent laparotomy to observe the degree of adhesion and closure of the mesenteric defect. RESULTS: No significant difference was found in the decrease in food intake and body weight among all groups. No internal hernia (IH) occurred in any group. The mesenteric defects of Group A remained completely visible without any closure or adhesion. Multiple gaps were found between the Prolene suture and the mesentery along the suture line in Group B. The mesenteric defects of Group C were complete closed with multiple adhesions of the small intestine and the greater omentum. The mesenteric defects in both Group D and Group E closed completely. The average adhesion scores in Group A and Group B were 0 and 0.33 ± 0.52 respectively. The average adhesion score in group C (3.83 ± 0.41) was higher than the other groups (p<0.05). The average adhesion scores in Group D and E were similar (3.17 ± 0.41 and 3.00 ± 0.00 respectively). CONCLUSION: Absorbable suture created a safe adhesion score between the mesentery which was not inferior to non-absorbable sutures.

Re-description and molecular characterisation of Choricotyle australiensis Roubal, Armitage & Rohde, 1983 (Monogenea: Diclidophoridae) infecting Chrysophrys auratus (Forster) (Perciformes: Sparidae).

Choricotyle australiensis Roubal, Armitage & Rohde, 1983, a diclidophorid monogenean species, is redescribed and genetically characterised using the partial nuclear 28S ribosomal RNA gene (28S rRNA) and a fragment of mitochondrial cytochrome c oxidase subunit 1 (cox1) gene sequences for specimens collected from Chrysophrys auratus (Forster) off Australia and New Zealand. Previous studies have either provided morphological or genetic results, whereas this study combines morphological and advanced molecular methods. A total of 70 Ch. auratus were examined with 22 individuals of C. australiensis recovered from the gills (overall prevalence of 23%). This study has provided the first evidence for the exploration of mitochondrial cox1 region for C. australiensis. Comparison of the newly generated sequences with other available data supported the distinction of C. australiensis among diclidophorid Furhmann, 1928 species thus confirming its taxonomic status.

Genetic and morphological characterization of Mawsonascaris vulvolacinata n. sp. (Nematoda: Anisakidae) and associated histopathology in a wild caught cowtail stingray, Pastinachus ater.

There are limited reports of infectious agents affecting Australian cowtail stingrays. In the present study, a new species of ascaridoid nematode belonging to the genus Mawsonascaris is described. The most distinct characteristic features were observed in females (the presence of a polar spine in the eggs and a flap-like projection in the vulval area). An identification key for Mawsonascaris spp. is provided. Additionally, internal transcribed spacers (ITS) sequences were obtained for the new species. Alignment of the ITS sequence of the specimens in the present study with those deposited in GenBank showed that there exists no other highly similar sequence. Phylogenetic analyses resulted in a distinct grouping of our specimens supporting morphological distinction from previously described Mawsonascaris spp. Histology was used to investigate the pathology caused by the infection. Necrosis, inflammation and fibrosis were evident at the border of the nodules formed by parasite. A large number of parasites were present in muscularis mucosae and submucosa but not in the muscularis of the stomach. The parasites were associated with an increased inflammatory response, which was also found in the muscularis mucosae and submucosa. Similar pathology has been described in elasmobranchs infected by cestodes, although with more severe lesions.