Are we ready to get rid of the terms “chalimus” and ”preadult” in the caligid (crustacea: copepoda: caligidae) life cycle nomenclature?

In view of recent studies, we suggest that the term “preadult” should not be used in scientific reports on Copepoda parasitic on fishes as having no explicit meaning or further justification. Consequently, the term “chalimus” with its use currently restricted in the Caligidae to at most two instars in the life cycles of species of Lepeophtheirus, also becomes redundant. In our new understanding, both the chalimus and preadult stages should be referred to as the respective copepodid stages (II through V, in integrative terminology). The terminology for the caligid copepod life cycle thereby becomes consistent with that for the homologous stages of other podoplean copepods. We see no justification for keeping “chalimus” and “preadult” even as purely practical terms. To justify this reinterpretation, we comprehensively summarize and reinterpret the patterns of instar succession reported in previous studies on the ontogeny of caligid copepods, with special attention to the frontal filament. Key concepts are illustrated in diagrams. We conclude that, using the new integrative terminology, copepods of the family Caligidae have the following stages in their life cycles: nauplius I, nauplius II (both free-living), copepodid I (infective), copepodid II (chalimus 1), copepodid III (chalimus 2), copepodid IV (chalimus 3/preadult 1), copepodid V (chalimus 4/preadult 2), and adult (parasitic). With this admittedly polemical paper, we hope to spark a discussion about this terminological problem

A New species of Parasitic copepod, Nemesis santhadevii (Siphonostomatoida: Eudactylinidae) from the gills of the Coral catshark Atelomycterus marmoratus, from Kota Kinabalu, Malaysia

The copepod Nemesis santhadevii sp. nov. (Siphonostomatoida: Eudactylinidae), which is parasitizing the gill filaments of the Coral catshark Atelomycterus marmoratus (Anonymous (Bennett), 1830) off Kota Kinabalu waters, Malaysia, is described and illustrated in this article. The new species Nemesis santhadevii prominently differs from its congeners in the following features: (1) the cephalothorax sub-circular is 1.3 times as wide as long and overlapping the second pedigerous somite; (2) the fifth somite is 0.4 times the width of the fourth; (3) the genital double somite is slightly narrower than the fifth; (4) the lowest cephalothoracic shield’s body length (0.20:1) proportion; (5) the caudal rami is ovate, it has two large and three small setae; (6) and the second somite has antenna with a patch of 34–38 spinules. It is the first record of parasitic eudactilinid copepod from Sabah, East Malaysia. A checklist of global valid species of Nemesis Risso, 1826, is provided

Marine collagen: purification, properties and application

Collagens are abundant structural proteins found in connective tissues such as bones, swim bladder, skin, blood vessels, intestines, and cartilage. They make up around 30% of the total protein. The purpose of this paper is to provide a summary of the current knowledge about collagen isolated from marine organisms and its possible applications. Collagen is widely used in pharmaceuticals, food, biomedical and cosmetic industries due to its cell adhesion, biocompatibility, and safety properties. This review discusses various methods for extracting collagen from marine vertebrates and its physicochemical properties. Enzymatic extractions might be a more effective at extracting collagen than acidic extractions. Peptides derived from collagen hydrolysates have biological activity that promotes health and relieves symptoms caused by chronic diseases. Aquaculture can help with collagen availability but an integrated technology for processing raw materials is necessary to address the negative effects of production waste. Marine collagen has many benefits over terrestrial sources including its versatility in healing skin damage and slowing down the aging process. The advantages of marine collagen over terrestrial sources are discussed along with its potential biotherapeutic applications in bone and skin injuries. The development of effective cosmetic products can become a strategic direction for technological development

A new species of parasitic copepod of the genus lernaeenicus lesueur, 1824 (siphonostomatoida: pennellidae) from the torpedo scad megalaspis cordyla (linnaeus) off Kerala coast of Arabian Sea, India

A new species of parasitic copepod of the genus Lernaeenicus Lesueur, 1824 (Siphonostomatoida: Pennellidae) parasitizing the torpedo scad Megalaspis cordyla (Linnaeus) collected from the Arabian Sea, off Kerala coast, India is described and illustrated. The new species, Lernaeenicus megalaspis sp. nov., can be distinguished from its other 32 congeners by the following features: (i) cephalosome 1.5 times longer than broad; (ii) presence of three stout posterior horns on the cephalosome, one median and two lateral, all sub-similar and apically round and blunt; (iii) neck 4.6 times as long as trunk; (iv) abdomen slightly longer than trunk; (v) 4-segmented antennule, and (vi) maxilla, third segment narrow, longer than second, segment 1 slightly broader than others and lateral border with two small spine

Deep neural network models for colon cancer screening

Early detection of colorectal cancer can significantly facilitate clinicians’ decision-making and reduce their workload. This can be achieved using automatic systems with endoscopic and histological images. Recently, the success of deep learning has motivated the development of image- and video-based polyp identification and segmentation. Currently, most diagnostic colonoscopy rooms utilize artificial intelligence methods that are considered to perform well in predicting invasive cancer. Convolutional neural network-based architectures, together with image patches and preprocesses are often widely used. Furthermore, learning transfer and end-to-end learning techniques have been adopted for detection and localization tasks, which improve accuracy and reduce user dependence with limited datasets. However, explainable deep networks that provide transparency, interpretability, reliability, and fairness in clinical diagnostics are preferred. In this review, we summarize the latest advances in such models, with or without transparency, for the prediction of colorectal cancer and also address the knowledge gap in the upcoming technology

First Report on Infection of Argulus quadristriatus (Arthropoda: Crustacea: Branchiura) on Marine Fish Cobia in Brood Stock Pond Culture [2019]

A total of 30 specimens of fish cobia Rachycentron canadum (Total Length = 45–120 cm, Weight = 3.0–25 kg) were stocked at the density of 1 kg/m³ in the polythene lined earthen pond. After 3 months of stocking, fish cobia was found with infection of ectoparasites. Then fishes were sampled at fortnight interval to find the percentage distribution of ectoparasites in different parts of the body for a year and also any pathological symptoms. Identification of the parasite was made through light and electron microscopies. The parasite was identified as Argulus quadristriatus Devaraj and Ameer Hamsa, 1977 (Crustacea: Branchiura: Argulidae) commonly called as fish lice. The maximum distribution of pathogenic argulid was observed on the head and operculum of cobia and was found high in summer months from April to June. Pathological symptoms were observed on cobia as erratic swimming, rubbing against substrate in the pond and lesions of epithelial tissues on the infected regions. It must be due to continuous rupturing and feeding of argulids on the skin of cobia using its powerful antennae. Scanning electron micrographs revealed some important morphological features of A. quadristriatus. This is a first report of A. quadristriatus infection on cobia reared in a land-based pond ecosystem

Exploring the sources and potential applications of marine collagenases

Collagenases are the most important group of collagenolytic proteases due to their multifarious catalytic potential and broad commercial applications. This review of the literature highlights the potential applications of collagenases in the food and medical industries as necessary components for bioactive functional ingredients and in the preparation of useful peptides. Due to their collagenolytic activity, they are critical factors that play a role in the global degradation of the extracellular matrix of animals. Marine organisms serve as a rich reservoir for the isolation and characterization of novel bioactive compounds, including hydrolytic enzymes. Despite the abundance of biological resources in the marine environment, very few of these commercially popular enzymes have been isolated from marine sources. There is a knowledge gap regarding the marine collagenase-producing organisms and the significance of the applications of this enzyme. This review summarizes the properties of collagenases isolated from marine organisms and discusses their potential applications. Furthermore, the critical challenges for the potential applications of collagenases in food and medical industries and their importance in biotechnology are also discussed here

Antiparasitic activity of the medicinal plant Dillenia suffruticosa against the marine leech Zeylanicobdella arugamensis (Hirudinea) and its phytochemical composition

Zeylanicobdella arugamensis (Annelida: Hirudinea), a marine parasitic leech, is currently affecting different species of cultured groupers, hybrid groupers, snappers and sea bass in Malaysia. Dillenia suffruticosa (Dilleniaceae), a medicinal plant found in Sabah, has been selected in our experiment to kill the leeches as a natural control method. The leech‐infested hybrid groupers were collected from aquaculture facilities, and the isolated leeches were challenged against methanol extract of D. suffruticosa leaves. The experiment was carried out using various concentrations of the extracts such as 25, 50 and 100 mg/ml. The methanol extract showed significant antiparasitic activity against Z. arugamensis with 100% mortality at a concentration of 100 mg/ml in 14.39 ± 3.75 min., followed by 50 and 25 mg/ml in 32.97 ± 9.29 and 41.77 ± 5.40 min., respectively. The phytochemical composition of the extract was determined using GC‐MS analysis to understand the nature of the principal compounds responsible for its antiparasitic properties. The leaves of D. suffruticosa demonstrated the presence of different bioactive compounds of various natures with varying percentages. Thus, it could be revealed that the methanol extract of D. suffruticosa mainly contains vital phytochemical compounds and showed an effective antiparasitic activity against the harmful leeches of hybrid groupers

Discovery of the fish host of the ‘planktonic’ caligid Caligus undulatus Shen & Li, 1959 (Crustacea: Copepoda: Siphonostomatoida)

The siphonostomatoid copepod Caligus undulatus Shen & Li, 1959 has been widely reported from plankton samples obtained from neritic and oceanic waters off coasts of the Indo-West Pacific and Atlantic Oceans. Until now, its fish host has remained unknown. This copepod belongs to an intriguing group of congeners that, despite being part of a chiefly parasitic group, are consistently found as zooplankters. Quite unexpectedly, in October 2019, a fish host of C. undulatus was discovered in the Seto Inland Sea, Japan—namely, the Japanese sardinella Sardinella zunasi (Bleeker, 1854). Both juvenile (chalimus) and adult individuals of this caligid were observed as parasites of the fish host. The discovery suggests that the species has an alternative life cycle as previously proposed for other purportedly ‘planktonic’ congeners and might frequently switch hosts during the adult stage. Thus, the C. undulatus group is newly proposed as a species group in the genus, in which five species are known as planktonic. Some hypotheses on the modified life cycle of caligids also briefly discussed

Hepatoprotective Potential of Malaysian Medicinal Plants: A Review on Phytochemicals, Oxidative Stress, and Antioxidant Mechanisms

Hepatotoxicity is a major global public health concern. Despite advances in modern medicine, the demerits of chemically prepared drugs outweigh their merits. In addition, the treatment of liver diseases based on modern medical principles has been found to produce several undesired side effects. Therefore, the exploration of medicinal plants has gained worldwide attention for treating various diseases, including liver diseases, owing to their potential efficacy and cost effectiveness. Several plants, including Andrographis paniculata, Bauhinia purpurea, Commelina nudiflora, Dillenia suffruticosa, Elaeis guineensis, Lygodium microphyllum, and Nephrolepis biserrata, have been reported with hepatoprotection. Moreover, these plants have been shown to play a vital role in ameliorating cellular damage because they contain several phytochemicals, including alkaloids, saponins, flavonoids, tannins, terpenoids, steroids, polyphenols, and diterpenoid lactones. The following antioxidant, anti-inflammatory, immunomodulatory, and hepatoprotective compounds have been found in these plants: andrographolide, rosmarinic acid, phenol, eugenol, 9,12-octadecadienoic, n-hexadecanoic acid, dihydroxy dimethoxy flavone, sitosterol, demethoxycurcumin, quercetin, linoleic acid, stigmasterol, kojic acid, indole-2-one, α-terpinol, linalool, kaempferol, catechin, ellagic acid, and oleanolic acid. This paper aimed to provide an in-depth review of in vivo studies on Malaysian medicinal plants possessing hepatoprotective properties, phytochemical ingredients, and antioxidant mechanisms, with an emphasis on the species proven particularly useful for treating hepatic disorders