Description of Maritrema portucalensis sp. nov. (Digenea, Microphallidae) parasite of Carcinus maenas (Crustacea, Decapoda) from Aveiro estuary, Northern Portugal

Abstract

Maritrema portucalensis sp. nov. (Digenea, Microphallidae) from Aveiro estuary, northern Portugal, is described on the basis of excysted metacercariae obtained from the gill lamellae of the shore crab Carcinus maenas (L.). M. portucalensis sp. nov. most closely resembles Maritrema subdolum Jägerskiöld, 1909, a species that also frequently uses C. maenas as second intermediate host. The new species differs from M. subdolum in having a narrower body at the level of testes and a smaller ovary and testes. Also, the digestive caeca presented various folds along their length, thickening in the terminal region. Moreover, the body surface was fully covered by tegumental spines provided with several teeth. To complement our morphological characterization and to identify M. portucalensis metacercariae, the ITS1 rDNA region of the cysts isolated from C. maenas was sequenced and compared with the corresponding available sequences of digenean trematodes belonging to the family Microphallidae. Alignments revealed 28 base-pair differences between the query-ITS1 and that of M. subdolum, and more importantly a 100% similarity with the sequence of Microphallidae sp. no. 15 cercaria from the snail Hydrobia ulvae. The last observation allowed us to establish an unequivocal association between cercaria known as Microphallidae sp. no. 15, and the metacercaria of M. portucalensis sp. nov. characterized in this work, contributing decisively to the clarification of its life cycle.

Green crab Carcinus maenas symbiont profiles along a North Atlantic invasion route

“…The European shore crab C. maenas is associated with a wide range of symbiotic fauna in both its native and invasive ranges, much of which is reviewed in Shields et al (2015), but also includes chordates, bryozoans (McIntosh 1865, Duerden 1893, Richard 1899, crustaceans, helminths (McIntosh 1865, von Linstow 1878, Monticelli 1890, Hall 1929, Rankin 1940, Bourdon 1965, James 1969, Prévot & Deblock 1970, Vivares 1971, Moravec 2007, Pina et al 2011, protists (Chatton & Lwoff 1935, Couch 1983, Stentiford et al 2004, fungi (Cuénot 1895, Bojko et al 2017a, bacteria (Perkins 1967, Comely & Ansell 1989, Eddy et al 2007 and viruses (Sindermann 1990, Stentiford & Feist 2005, Bateman & Stentiford 2017. Often, in-depth knowledge of the symbionts carried by invasive organisms is lacking (Roy et al 2017).…”

Maritrema patagonican. sp. (Digenea: Microphallidae) cultured from Metacercariae from Freshwater Anomuran,Aeglaspp. (Decapoda: Aeglidae), in Patagonia

“…(oral: 23-29, ventral: 24-30). Further, the new species has a smaller metacercarial cyst (240-288 long by 192-222 wide) than both M. orensense (270-307 long) and M. jebuensis (300 long by 300 wide), but it is bigger than that of M. portucalensis (178-187 long) (Deblock, 1971;Chung et al, 2010;Pina et al, 2011;Alda et al, 2013).…”

A review on the molecular characterization of digenean parasites using molecular markers with special reference to ITS region

“…The worker observed the uniform patterns of repetitive 130 bp sequences in ITS-1 region in microphallid species. Pina et al (2011a) morphologically and molecularly characterized Maritrema portucalensis sp. nov. from crab using 18S, ITS-1 and 5.8S rDNA sequences.…”