Review of the global distribution and hosts of the economically important fish parasitic isopod genus Ceratothoa (Isopoda: Cymothoidae), including the description of Ceratothoa springbok n. sp. from South Africa

Phylogeny and ultrastructure of Elthusa raynaudii (Isopoda, Cymothoidae) firstly recorded from the invasive silver cheeked toadfish (Lagocephalus sceleratus) (Gmelin 1789) in eastern Mediterranean Sea coast

With the opening of the Suez Canal in 1869, many changes have occurred in the Mediterranean Sea ecosystem so became a home to many invasive Lessepsian marine species that have migrated from the Red Sea. About 500 marine species including pufferfish have immigrated and rapidly established a population in the Mediterranean Sea causing significant impact on its ecosystem and fisheries sector. The parasitic fauna of these pufferfish has scarcely been studied in the Mediterranean Sea and also in their native habitat. During this surveillance study on the invasive pufferfish species from the Egyptian Mediterranean coast, the female cymothoid isopod Elthusa raynaudii was detected from the branchial cavity and also in the buccal cavity of 23.9% of the examined Lagocephalus sceleratus. The isolated isopod species was firstly identified and described through electron microscopy and molecular phylogeny based on the sequences of mitochondrial 16S rRNA gene. Additionally, the description of eggs, embryonic stage, and manca of E. raynaudii was firstly provided. The pathological impact on the infested fish tissues was investigated and revealed curling and loss of secondary gill lamellae in addition to mucous exudates in between the gill filaments and granuloma formation in the gill arch. The study provided the first report of L. sceleratus as a new host for the isopod E. raynaudii collected from the Egyptian Mediterranean coast as a new locality record. The role of the Lessepsian invasive pufferfish in transmitting parasites to the native fish species was discussed.

Review and guide to the isopods (Crustacea, Isopoda) of littoral and sublittoral marine habitats in the Southern California Bight

The isopod crustaceans reported from or expected to occur in littoral and sublittoral marine habitats of the Southern California Bight (SCB) in the northeastern Pacific Ocean are reviewed. A total of 190 species, representing 105 genera in 42 families and six suborders are covered. Approximately 84% of these isopods represent described species with the remaining 16% comprising well-documented "provisional" but undescribed species. Cymothoida and Asellota are the most diverse of the six suborders, accounting for ca. 36% and 29% of the species, respectively. Valvifera and Sphaeromatidea are the next most speciose suborders with between 13-15% of the species each, while the suborder Limnorioidea represents fewer than 2% of the SCB isopod fauna. Finally, the mostly terrestrial suborder Oniscidea accounts for ca. 5% of the species treated herein, each which occurs at or above the high tide mark in intertidal habitats. A key to the suborders and superfamilies is presented followed by nine keys to the SCB species within each of the resultant groups. Figures are provided for most species. Bathymetric range, geographic distribution, type locality, habitat, body size, and a comprehensive list of references are included for most species.

Triple barcoding for a hyperparasite, its parasitic host, and the host itself: a study of Cyclocotyla bellones (Monogenea) on Ceratothoa parallela (Isopoda) on Boops boops (Teleostei)

Cyclocotyla bellones Otto, 1823 (Diclidophoridae) is a monogenean characterised by an exceptional way of life. It is a hyperparasite that attaches itself to the dorsal face of isopods, themselves parasites in the buccal cavity of fishes. In this study, Cy. bellones was found on Ceratothoa parallela (Otto, 1828), a cymothoid isopod parasite of the sparid fish Boops boops off Algeria in the Mediterranean Sea. We provide, for the first time, molecular barcoding information of a hyperparasitic monogenean, the parasitic crustacean host, and the fish host, with COI sequences.

Morphological description and molecular characterisation of a new species of Anilocra Leach, 1818 (Crustacea: Isopoda: Cymothoidae) from India

A fish parasitic isopod recently reported from India as Anilocra leptosoma Bleeker, 1857, was re-examined and morphologically compared to five closely related species: A. capensis Leach, 1818, A. clupei Williams and Bunkley-Williams, 1986, A. leptosoma Bleeker, 1857, A. paulsikkeli Welicky and Smit, 2019 and A. pilchardi Bariche and Trilles, 2006. This species was sequenced and compared to other known Anilocra species based on mitochondrial cytochrome c oxidase subunit I (COI) gene fragments. Both morphological and molecular data corroborate that the Anilocra species parasitising the clupeid fish Tenualosa toli (Valenciennes, 1847) from India should be recognised as a new species, and we describe Anilocra grandmaae n. sp. based on the holotype and paratype females. The key characters of A. grandmaae n. sp. include the body being less than 4.0 times as long as wide; antennula article 3 anterodistal margin expanded, 1.2-1.4 times as wide as long; pleonite 1 concealed by pereonite 7 and lateral margin posteriorly produced; pereopods 1-4 with three nodules on dactylus; endopod of pleopods 3-5 with a proximomedial lobe and folding; and pleotelson ovate, with lateral margins converging smoothly to a caudomedial point.