Cymothoa frontalis, a cymothoid isopod parasitizing the belonid fish Strongylura strongylura from the Malabar Coast (Kerala, India): redescription, description, prevalence and life cycle

Abstract

Background: Cymothoa frontalis Milne Edward, 1840 is a very poorly described cymothoid, notwithstanding the previous redescription of the female. Pertinently, to date, the host of C. frontalis has not been identified with adequate precision. Most of the descriptions of cymothoids carried out hitherto were based primarily on females, but practically ignoring other life cycle stages. The present paper redescribes the female and describes other life cycle stages of the species C. frontalis to get better precision in their identification. Results:The female phase of C. frontalis is redescribed according to type specimens extant in the NMNH, Paris, and also by the data obtained from live specimens collected during the present study. The general morphology and appendages of various life cycle stages of the species are described. Among 80 fish species from 35 families examined, C. frontalis was recovered only from Strongylura strongylura signifying its oligoxenous host specificity, the prevalence and intensity being 68.65% and 1.9, respectively. Each host fish in more than 85% of the population was infested with a pair of C. frontalis, in three combinations, predominantly with male-female pair (70.9%). C. frontalis exhibited strict site specificity attaching to the buccal cavity of the host fish. The study has also identified three major phases (marsupial, free living and infective) in the life cycle of C. frontalis. The zygotic-staged marsupiumites were developed through five sequential ontogenetic stages. The manca released from the marsupium become infective after a brief period of free swimming life. During the infective phase, C. frontalis completes remaining life cycle stages with successive moulting. Further, six successive stages of the ovigerous females have also been identified. Conclusions: The present redescription of the female and the description of transitional, male, juvenile and larvae of C. frontalis facilitate precise identification of the species at any stage of the life cycle. Further, the strict host and site specificities of the parasite, as borne out from the present study, and its high degree of prevalence in the host make C. frontalis as an ideal model organism to study the strategies to be adopted for the management of parasites infesting edible fishes.

Exceptionally preserved cryptoniscium larvae - morphological details of rare isopod crustaceans from French Cretaceous Vendean amber

“…The data from extant species is expanded for better visibility and is outlined by a dotted bracket. (Fraisse, 1878;Bonnier, 1900;Thompson, 1901;Caullery, 1907;Miyashita, 1940;Nielsen and Strömberg, 1965;Bresciani, 1966;Nielsen, 1967;Bourdon, 1972Bourdon, , 1972Bourdon, , 1976Bourdon, , 1981Holdich, 1975;Schultz, 1975Schultz, , 1980Kensley, 1979;Bourdon and Bruce, 1980;Anderson and Dale, 1981;Coyle and Mueller, 1981;Dale and Anderson, 1982;Strömberg, 1983;Adkinson and Collard, 1990;Rybakov, 1990;Shields and Ward, 1998;Pascual et al, 2002;Torres Jordá, 2003;Shimomura et al, 2005;Hosie, 2008;Román-Contreras and Romero-Rodríguez, 2013;An et al, 2015;Serrano-Sánchez et al, 2016;Adlard and Lester, 1995;Atkins, 1933;Bruce, 2009;Brusca, 1978;McDermott, 2002;Romero-Rodríguez and Román-Contreras, 2008;Strömberg, 1971;Thamban et al, 2015;Truesdale and Mermilliod, 1977;Tsukamoto, 1981). common ancestor of cymothoids and epicarideans.…”

Shape of attachment structures in parasitic isopodan crustaceans: the influence of attachment site and ontogeny

“…The specimen is in a transitional stage between immature stage 2 and male, since it already has the last pair of pereopods fully developed, but poorly developed male characteristics (such as penes and appendix masculina on appendage of pleon segment 2). It is therefore referred to as an immature stage 3 or 'young male' (Trilles, 1975), during which the individual is already attached to a host and transforms into a male by moulting (see Brusca, 1978b;Aneesh et al, 2015). This stage was named by Brusca (1978b) as the 'aegathoid' stage.…”

“…For an individual still within the egg the case is easy and it is referred to as an embryo (Bakenhaster, McBride & Price, 2006). Aneesh et al (2015) distinguishes between three stages of an embryo.…”

“…These are the first detailed photographic images embryonic stages of Cymothoidae and the first images of embryos of the groups Ceratothoa and Elthusa. Only a few previous publications provided an illustration of one or more embryonic or marsupial stages of Cymothoidae: a developing embryo of Nerocila californica (see Brusca, 1978b); an embryo of Cymothoa liannae; a 'pre-hatch' of Anilocra pomacentri (see Adlard & Lester, 1995); an embryo of an unidentified Amazonian representative of Cymothoiiae (see Sartor, 1987); a Glossobius hemiramphii embryo see (Bakenhaster, McBride & Price, 2006); and an embryo of Cymothoa frontalis (see Aneesh et al, 2015). Aneesh et al (2016) and Aneesh et al (2018) both provided a photo of the embryos of Mothocya renardi and Agarna malayi, respectively.…”

New Host Record of Lutjanus gibbus for Parasitic Nerocila sp. (Crustacea, Isopoda, Cymothoidae) from South Andaman, Andaman Islands, India

“…The genus Nerocila associate with many species of commercially important fishes around the world and cause significant economic losses to fisheries by killing, stunting or damaging [3]. [24], Lithognathus mormyrus [25], Gymnothorax eurostus, Thryssa malabarica, Thryssa setirostris, Coilia dussumieri, Opisthopterus tardoore, scualosa thoracata and Ambassis ambassis [26], Sphyraena japonica, Trachurus japonicas, and Etrumeus micropus [27]. The genus Nerocila were reported so far from the different parts of the world including North America, Mediterranean Sea, California, eastern Pacific, Hong Kong and Australia, Yugoslavia, Kuwait, Adriatic Sea, Indo-West Pacific, Malaysia, Turkey, Lebanon, Algeria and India, and now this genus range was extending from Andaman Islands [ 24].…”