Henneguya (Cnidaria: Myxosporea: Myxobolidae) infections of cultured barramundi, Lates calcarifer (Perciformes: Latidae) in an estuarine wetlands system of Malaysia: description of Henneguya setiuensis n. sp., Henneguya voronini n. sp. and Henneguya calcarifer n. sp.

Abstract

Examination of 35 barramundi (Lates calcarifer) from aquaculture cages in Setiu Wetland, Malaysia, revealed a single fish infected with three Henneguya spp. (Cnidaria: Myxosporea). Characterization of the infections using tissue tropism, myxospore morphology and morphometry and 18S rDNA sequencing supported description of three new species: Henneguya setiuensis n. sp., Henneguya voronini n. sp. and H. calcarifer n. sp. Myxospores of all three species had typical Henneguya morphology, with two polar capsules in the plane of the suture, an oval spore body, smooth valve cell surfaces, and two caudal appendages. Spores were morphometrically similar, and many dimensions overlapped, but H. voronini n. sp. had shorter caudal appendages compared with H. calcarifer n. sp. and H. setiuensis n. sp. Gross tissue tropism distinguished the muscle parasite H. calcarifer n. sp. from gill parasites H. setiuensis n. sp. and H. voronini n. sp.; and these latter two species were further separable by fine-scale location of developing plasmodia, which were intralamellar for H. setiuensis n. sp. and basal to the filaments for H. voronini n. sp. small subunit ribosomal DNA sequences distinguished all three species: the two gill species H. setiuensis n. sp. and H voronini n. sp. were only 88% similar (over 1708 bp), whereas the muscle species H. calcarifer n. sp. was most similar to H. voronini n. sp. (98% over 1696 bp). None of the three novel species was more than 90% similar to any known myxosporean sequence in GenBank. Low infection prevalence of these myxosporeans and lack of obvious tissue pathology from developing plasmodia suggested none of these parasites are currently a problem for barramundi culture in Setiu Wetland; however additional surveys of fish, particularly at different times of the year, would be informative for better risk assessment.

Characterizing Two New Henneguya Species in the Respiratory Organs of African Sharptooth Catfish

“…The caudal projection in the present species H. qenabranchiae n. sp. was as long as H. voronini (Borkhanuddin et al, 2020), but the caudal projection in the present species H. qenasuprabranchiae n. sp. was shorter.…”

“…1 and 2 (Emeish et al, 2022). The body shape of the present two species differed from that of H. voronini (Borkhanuddin et al, 2020), and H. aegea (Katharios et al, 2020), where the body is more elongated. The body shape of the present species, H. qenabranchiae n.…”

“…described in the present study both had smooth surfaces, as previously described for H. voronini n. sp. (Borkhanuddin et al, 2020), H. aegea (Katharios et al, 2020) and Henneguya spp. 1 and 2 (Emeish et al, 2022).…”

Description of myxosporeans (Cnidaria: Myxozoa) infecting the popular food fish Notopterus notopterus (Pisces: Notopteridae) in Malaysia and India

“…All measurements are in micrometer (μm). Species Host Infection site Spore body Polar capsule Locality Reference Length Width Length Width Henneguya ganapatiae Notopterus notopterus Gills 9.7 ± 0.4 (9.3–10.0) 4.5 ± 0.5 (4.0–4.8) 3.3 ± 0.2 (3.2–2.6) 1.6 ± 0.1 (1.4–1.8) Uttar Pradesh, India Present study H. ganapatiae Notopterus notopterus Gill contents 9.9–10.0 4.0–4.4 3.21–2.6 1.4–1.8 Andra Pradesh, India Quadri, 1970 H. bicaudi Cirrihinus mrigala Gill filaments 21.0 6.2 3.1 2.0 Harike wetlands, Punjab, India Kaur and Attri, 2015 H. ophiocephali ophiocephalus punctatus Gills and muscles 41.5–52.5 6.2–7.2 6.2 9.3 West Bengal, India Chakravarty, 1939 H. chudharyi Channa punctatus Gill lamellae 10.5–13.2 (11.6 ± 1.1) 3.6–4.2 (3.8 ± 0.2) 5.5–7.2 (6.5 ± 0.6) 1.0–1.3 (1.1 ± 0.1) Uttar Pradesh, India Bajpai and Haldar, 1982 H. voronini Lates calcarifer Base of the gill filament 9.9 ± 0.3 (9.5–10.3) 5.9 ± 0.3 (5.8–6.0) 3.7 ± 0.2 (3.5–4.0) 2.1 ± 0.1 (2.0–2.2) Malaysia Borkhanuddin et al, 2020 H. setiuensis ...…”