Fish blood flukes (Digenea: Aporocotylidae) from Indonesia: Two new genera and species infecting the banded eagle ray, Aetomylaeus nichofii (Bloch and Schneider, 1801) Capapé and Desoutter, 1979 (Myliobatiformes: Myliobatidae) from Borneo

Abstract

Specimens representing two new species of blood flukes (Digenea: Aporocotylidae), each representing a new genus, were collected from the banded eagle ray, Aetomylaeus nichofii (Bloch and Schneider, 1801) Capapé and Desoutter, 1979, in Borneo, Indonesia. Aetohemecus kirstenjensenae n. sp., n. gen. infected the heart of a banded eagle ray from Manggar, East Kalimantan, Borneo, Indonesia, and differs from its congeners by having an oviducal ampullae, an oötype posterior to all genitalia, and a uterus that extends anterior to the ovary. The new species resembles Selachohemecus spp., which infect requiem sharks (Carcharhinidae) in the Northwestern Atlantic Ocean and Gulf of Mexico, by having a single ventrolateral row of large C-shaped tegumental spines, X- or H-shaped intestine, and a post-caecal ovary. Specimens of Homestios janinecairae n. sp., n. gen. infected the heart of a banded eagle ray from Takisung, South Kalimantan, Borneo, Indonesia. The new species resembles other blood flukes that infect rays (Batoidea) by having a single, curving testis and an inverse U-shaped intestine as well as by lacking tegumental spines. It differs from all aporocotylids infecting batoids that lack spines by having a uterus that extends anteriad beyond the level of the seminal vesicle. The present study comprises the first record of an aporocotylid from Indonesia or from an eagle ray (Myliobatidae). To our knowledge, these are the first trematodes reported from a species of Aetomylaeus . The proposals of new genera and the description of two new species herein brings the total number of nominal chondrichthyan blood flukes to 13 species of 11 genera.

Morphological features of the testis of freshwater blood flukes of the genus Sanguinicola Plehn, 1905, with consideration of the testicular patterns in the Aporocotylidae

“…The blood flukes infecting sharks, chimaeras and rays are characterized by a single large testis, occupying the middle 1/3 of their body and localatized immediately posterior to the intestinal bifurcation between two intestinal caeca. This information was found for the genera Hyperandrotrema (see Smith 2002;Orélis-Ribeiro et al 2013) and Selachohemecus (see ) in sharks, for the genus Chimaerohemecus (see Van der Land, 1967;Kamegai et al 2002) in chimaeras and for Aetohemecus (see (Warren and Bullard 2021) in rays. Furthermore, the blood flukes infecting rays of the genera Orchispirium (see , Electrovermis (see Warren and Bullard 2019), Achorovermis (see Warren et al 2020) and Homestios (see Warren and Bullard 2021) have a single, long testis, curving more 30 times with smooth testicular margins.…”

“…This information was found for the genera Hyperandrotrema (see Smith 2002;Orélis-Ribeiro et al 2013) and Selachohemecus (see ) in sharks, for the genus Chimaerohemecus (see Van der Land, 1967;Kamegai et al 2002) in chimaeras and for Aetohemecus (see (Warren and Bullard 2021) in rays. Furthermore, the blood flukes infecting rays of the genera Orchispirium (see , Electrovermis (see Warren and Bullard 2019), Achorovermis (see Warren et al 2020) and Homestios (see Warren and Bullard 2021) have a single, long testis, curving more 30 times with smooth testicular margins. Besides cartilaginous fishes, gnathostomata of the order Acipenseriformes, for which we have knowledge on blood flukes for the genus Acipensericola, are distinguished by a testicular column with 6 spheroid testes, each approximately equal in diameter (see .…”

Revision of Sanguinicola Plehn, 1905 with Redescription of Sanguinicola volgensis (Rašín, 1929) McIntosh, 1934, Description of a New Species, Proposal of a New Genus, and Phylogenetic Analysis

“…by having a Laurer’s canal. They further differ by having C-shaped lateral tegumental spines and a non-sinusoidal testis or lacking spines and having a sinusoidal testis ( Warren et al, 2019 ; Warren and Bullard, 2021 ).…”