RESUMO
We herein provide a supplemental description of Nomasanguinicola dentata (Paperna, 1964) Warren and Bullard, 2023 (Digenea: Sanguinicolidae) and provide a revised 28S phylogeny to test relationships among freshwater fish blood flukes. We examined the heart of three African sharptooth catfish, Clarias gariepinus (Burchell, 1822) Teugles, 1982 from the Kavango River (northeastern Namibia) that was infected with adults of N. dentata. This blood fluke differs from N. canthoensis by having a body 5.3-6.7 longer than wide (vs. 3.5-4.6), an anterior esophageal swelling 7-8% (vs. 14-24%) of total esophageal length, a posterior esophageal swelling 3-5% (vs. 8-10%) of total esophageal length, a pre-cecal (vs. wholly post-cecal) testis, and an ovary that does not extend laterally beyond the nerve cords. The 28S sequence for N. dentata differed from that of N. canthoensis by 144 bp (9% difference). The phylogenetic analysis recovered these species as sister taxa and Sanguinicolidae as monophyletic. This is the first report of a fish blood fluke from sub-Saharan Africa, and the first report of a species of Nomasanguinicola from Africa in â¼40 yrs.
Assuntos
Peixes-Gato , Doenças dos Peixes , Trematódeos , Feminino , Masculino , Animais , Filogenia , Rios , Namíbia , Doenças dos Peixes/epidemiologia , Trematódeos/genéticaRESUMO
During a 2021 parasitological survey of birds in the Nyae Nyae-Khaudum Dispersal Area (Kavango-Zambezi Transfrontier Conservation Area, Namibia), we collected 9 specimens of Dendritobilharzia pulverulenta (Braun, 1901) Skrjabin, 1924 infecting the blood (heart lumen) of a white-backed duck, Thalassornis leuconotus (Eyton, 1838) (Anseriformes: Anatidae), and a fulvous whistling duck, Dendrocygna bicolor (Vieillot, 1816) (Anatidae). These flukes were fixed for morphology and preserved for DNA extraction. We assigned our specimens to DendritobilharziaSkrjabin and Zakharow, 1920 because they were strongly dorso-ventrally flattened in both sexes and had an intestinal cyclocoel with a zig-zag common cecum with lateral dendritic ramifications, numerous testes posterior to the cyclocoel and flanking the dendritic ramifications, and a tightly compacted convoluted ovary as well as lacking an oral sucker, ventral sucker, and gynaecophoric canal. Further, our specimens were morphologically identical to previously published descriptions of D. pulverulenta. Sequences of the 28S from our specimens were nearly identical to those identified as D. pulverulenta from North America (New Mexico), and our 28S phylogenetic analysis recovered D. pulverulenta within a polytomy of other Gigantobilharziinae spp. The CO1 phylogenetic analysis recovered a monophyletic Dendritobilharzia and, with low taxon sampling, a monophyletic Gigantobilharzia. This is the first record of a species of Dendritobilharzia infecting these ducks as well as the first record of an adult Dendritobilharzia from sub-Saharan Africa. The original description of adult D. pulverulenta (type locality: northern Sudan) was based on 2 males only, and hence the present study is the first description of female D. pulverulenta from Africa (the continent of the type locality). We reassign 2 Gigantobilharziinae spp. based on morphology and nucleotide evidence: Gigantobilharzia ensenadense (Lorenti, Brant, Gilardoni, Diaz, and Cremonte, 2022) Dutton and Bullard, n. comb., and Gigantobilharzia patagonense (Lorenti, Brant, Gilardoni, Diaz, and Cremonte, 2022) Dutton and Bullard, n. comb. We also comment on several avian schistosome sequences whose identities need confirmation or that likely have been misidentified.
Assuntos
Aves , Schistosomatidae , Animais , Masculino , Feminino , Filogenia , Namíbia , Schistosomatidae/genética , PatosRESUMO
We herein describe Paraharmotrema karinganiense n. gen., n. sp. Dutton & Bullard (Liolopidae Dollfus, 1934) from specimens infecting the intestine of the serrated hinged terrapin (Pelusios sinuatus), east African black mud turtle (Pelusios subniger) (both Nwanedzi River, Mozambique), and South African helmeted terrapin (Pelomedusa galeata) (North-western Zululand, KwaZulu-Natal Province, South Africa). The new genus can be easily differentiated from the other accepted liolopid genera (Liolope Cohn, 1902; Helicotrema Odhner, 1912; Harmotrema Nicoll, 1914; Dracovermis Brooks & Overstreet, 1978) by the combination of having a linguliform body approximately 6-9 × longer than wide, tegumental spines/scales, a minute ventral sucker located in the anterior 1/7-1/8 of the body, deeply lobed testes that are transverse and abut the caeca (spanning the intercaecal space), a uterus that is lateral to the anterior testis (not ventral to the anterior testis), a lobed ovary that is dextral and nearest the posterior testis, and a vitellarium that does not extend anteriad to the level of the ventral sucker and that does not fill the intercaecal space. Nucleotide sequences of large subunit ribosomal DNA (28S) and internal transcribed space region (ITS2) from all analyzed specimens of the new species were identical, respectively; the 28S sequences differed from that of Liolope copulans Cohn, 1902 and from that of Harmotrema laticaudae Yamaguti, 1933 by 103 (8%) and 105 (8%) nucleotides, respectively. The 28S phylogenetic analysis recovered the new genus sister to a clade comprising L. copulans and H. laticaudae. A key to liolopid genera is provided herein. The present study comprises the first nucleotide-based phylogenetic placement of Harmotrema and first record of a liolopid from South Africa or Mozambique. It is the first proposal of a new liolopid genus in 43 yrs, and it documents a second liolopid genus from P. subniger while tripling the number of liolopid turtle hosts reported from the continent of Africa.