The present paper comprises a systematic survey of adult nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southeastern Mexico, in 1993-1994. Examinations of a total of 533 fishes (17 species) originating from 39 cenotes from the Mexican states of Yucatan and Quintana Roo revealed the presence of the following nine nematode species: Rhabdochona (Rhabdochona) kidderi, Procamallanus (Spirocamallanus) rebecae, P. (S.) neacaballeroi, Philome-trnides caudata, Hysterothylacium cenotae, Pseudocapillaria yucatanensis, Paracapillaria rhamdiae, P. teixerafreitasi and Capillostrongyloides sp. (only females). Four species (R. kidderi, P. rebecae, P. neacaballeroi and Capillostrongyloides sp.) are briefly described and illustrated and some problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Taxonomic changes include Procamallanus (Spirocamallanus) neacaballeroi (Caballero-Deloya, 1977) comb. n. and Procamallanus (Spirocamallanus) rebecae (Andrade-Salas, Pineda-López ct Garcfa-Magana, 1994) comb. n. The nematode fauna of fishes in cenotes of the Yucatan Peninsula shows its appurtenance to the Neotropical fauna with close affinities with that of fish nematodes from South America, but with a considerable degree of endemism.
Bentholebouria colubrosa gen. n. et sp. n. (Digenea: Opecoelidae) is described in the wenchman, Pristipomoides aquilonaris (Goode et Bean), from the eastern Gulf of Mexico, and new combinations are proposed: Bentholebouria blatta (Bray et Justine, 2009) comb. n., Bentholebouria longisaccula (Yamaguti, 1970) comb. n., Bentholebouria rooseveltiae (Yamaguti, 1970) comb. n., and Bentholebouria ulaula (Yamaguti, 1970) comb. n. The new genus is morphologically similar to Neolebouria Gibson, 1976, but with a longer cirrus sac, entire testes, a rounded posterior margin with a cleft, and an apparent restriction to the deepwater snappers. Morphologically, the new species is closest to B. blatta from Pristipomoides argyrogrammicus (Valenciennes) off New Caledonia but can be differentiated by the nature of the internal seminal vesicle (2-6 turns or loops rather than constrictions), a longer internal seminal vesicle (occupying about 65% rather than 50% of the cirrus sac), a cirrus sac that extends further into the hindbody (averaging 136% rather than 103% of the distance from the posterior margin of the ventral sucker to the ovary), and a narrower body (27% rather than 35% mean width as % of body length). A Bayesian inference analysis of partial sequence of the 28S rDNA from Neolebouria lanceolata (Price, 1934), Cainocreadium lintoni (Siddiqi et Cable, 1960), Hamacreadium mutabile Linton, 1910, Opecoeloides fimbriatus (Linton, 1910), Podocotyloides brevis Andres et Overstreet, 2013, the new species, and previously published comparable sequences from 10 opecoelid species revealed two clades. One clade includes deep-sea (≥ 200 m) and freshwater fish opecoelids + Opecoeloides Bremser in Rudolphi, 1819, and a second clade included those opecoelids from shallow-water marine, perciform fishes.
The developmental stages and life cycle of the nematode Camallanus anabantis Pcarse, 1933 an intestinal parasite of Anabas testudineus (Bloch) arc described. The copepod Mesocyclops leuckarti (Claus) was used as experimental intermediate host. After being ingested by the copepods the nematode first-stage larvae enter its haemocoel, where they moult twice, 4 d.p.i. and 11 d.p.i., at 21-26°C, respectively to become the infective third-stage larvae. The definitive fish hosts become infected when feeding on copcpods harbouring infective larvae. In the fish host’s intestine the larvae undergo two more moults, the third on day 15 p.i. The fourth moult of “male” larvae occurred on day 68 p.i. and that of “female” larvae on day 86 pi. at water temperatures 24-36°C- A female with eggs and few larvae in the uteri was first observed on day 187 p.i.
In the present study, we determine the presence of parasites in fish larvae collected from nearshore waters along the northern and central coast of Chile. The parasites were identified to the lowest possible taxonomic level based on morphological and molecular analyses. The fish sample was composed of 5 574 fish larvae. Of these, 3% harboured only larval ectoparasitic copepods whereas no endoparasites were found in the 1 141 fish evaluated for this group of parasites. The parasitic copepods collected were initially classified as 'morphotypes' according to differences in morphological characteristics. They were then analysed using molecular techniques based on the 28S and COI genes. Seven morphotypes of parasitic copepods (mostly at chalimus stages) were recognised: two of the morphotypes belonged to Pennellidae Burmeister, 1835, three to Caligidae Burmeister, 1835 and two were not identified. Only five morphotypes of copepods were analysed using molecular sequences, which confirmed the existence of six species: two pennellids of the genus Trifur Wilson, 1917 and two caligids of the genus Caligus Müller, 1785, plus two additional species that were morphologically different from these taxa. The pennellids were present in several fish species, being generally more prevalent than the caligids, in both the central and northern localities of Chile. Multispecies infections in larval fish were infrequent (< 1%). We conclude that fish larvae were rich in parasites, considering that these hosts exhibited small body sizes and were very young. We suggest that fish larvae could play a role, as intermediate hosts, in the life cycle of the parasitic copepods found., Gabriela Muñoz, Mauricio F. Landaeta, Pamela Palacios-Fuentes, Zambra López, María Teresa González., and Obsahuje bibliografii
Polyploidie je důležitým evolučním mechanismem přispívajícím k biodiverzitě současných ryb a také významným nástrojem v akvakultuře. Tento článek podává přehled o mechanismech vzniku polyploidie a o kauzálním vztahu mezi hybridizačními událostmi a zvýšením stupně ploidie. Uvádí rovněž příklady využití specifických vlastností polyploidů v akvakultuře., Polyploidy is an important evolutionary mechanism contributing to the biodiversity of extant fishes, and it also represents a notable tool in aquaculture. This paper reviews the mechanisms by means of which polyploidy arises and the causal relationship between hybridisation events and elevation of the ploidy level. Utilization of specific traits of polyploids in aquaculture is also discussed., Martin Flajšhans, Petr Ráb., and Obsahuje seznam literatury
A comparative study of the scoleces of monozoic tapeworms (Cestoda: Caryophyllidea), parasites of catostomid and cyprinid fishes (Teleostei: Cypriniformes) in the Nearctic Region, was carried out using light and scanning electron microscopy. Scoleces of 22 genera of North American caryophyllideans were characterised and their importance for taxonomy, classification and phylogenetic studies was critically reviewed. Nearctic genera exhibit a much higher variation in the shape and form of scoleces compared with taxa in other biogeographical regions. The following basic scolex types can be recognised in Nearctic caryophyllideans: monobothriate (Promonobothrium Mackiewicz, 1968), loculotruncate (Promonobothrium, Dieffluvium Williams, 1978), bothrioloculodiscate (Archigetes Leuckart, 1878, Janiszewskella Mackiewicz et Deutsch, 1976, Penarchigetes Mackiewicz, 1969, Pseudoglaridacris Oros, Uhrovič et Scholz, 2018), fixomegabothriate (Capingens Hunter, 1927), bulbate and bulboacuminate (Atractolytocestus Anthony, 1958), cuneiloculate (Hypocaryophyllaeus Hunter, 1927, Rowardleus Mackiewicz et Deutsch, 1976, Spartoides Hunter, 1929), biacetabulate, bulboloculate, bothrioloculodiscate (Biacetabulum Hunter, 1927), tholate (Hunterella Mackiewicz et McCrae, 1962), cuneifimbriate (Khawia Hsü, 1935), cuneiform (Calentinella Mackiewicz, 1974, Caryophyllaeides Nybelin, 1922, Edlintonia Mackiewicz, 1970), hastate (Pseudolytocestus Hunter, 1929), loculotholate (Bialovarium Fischthal, 1953, Pliovitellaria Fischthal, 1951), and cuneiformoloculate (Glaridacris Cooper, 1920, Isoglaridacris Mackiewicz, 1965). The same type of scolex may be shared by species of different genera or families and species of the same genus can have a scolex of conspicuously different morphology, e.g. in Promonobothrium. Scolex morphology may be therefore of limited use in generic designation., Mikuláš Oros, Dalibor Uhrovič, Anindo Choudhury, John S. Mackiewicz and Tomáš Scholz., and Obsahuje bibliografii