Aquatic Parasitology Laboratory, School of Fisheries, Aquaculture, and Aquatic Sciences, College of Agriculture, Auburn University, Auburn, Alabama 36849.
Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, St. Petersburg, Florida 33701.
J Parasitol. 2021 Jan 1;107(1):59-73. doi: 10.1645/20-89.
Cardicola Short, 1953 is the most speciose aporocotylid genus (35 species) and includes marine and estuarine species of fish blood flukes that infect "higher ray-finned fishes" (Euteleostei). Several clades within Cardicola are recovered in phylogenetic analyses of the large subunit ribosomal DNA (28S), but morphological synapomorphies for those nucleotide-based clades remain elusive. The type species, Cardicola cardiocola (Manter, 1947) Short, 1953, has not been recollected in 73 yr and the original description was incomplete; making a genus revision challenging because of the ambiguous systematic position of its type species. Herein, we redescribe C. cardiocola by using the holotype (USNM 1337732) and new specimens collected from the type host, jolthead porgy, Calamus bajonado (Sparidae), from nearby the type locality. It differs from its congeners by the combination of having a body that is 5 times longer than wide, an anterior sucker with concentric rows of spines, 2-6 tegumental body spines per row, an esophageal gland that is 22-43% of the esophageal length, a testis that is 3-5 times longer than wide and that fills the intercecal space, a vitelline duct connecting to the anterior aspect of the oötype, an ascending uterus that lacks any coil, a descending uterus yielding a single coil, an obvious cirrus sac separated by constriction from the seminal vesicle, a tegumental protrusion surrounding the terminal end of cirrus sac, and a male genital pore that is posterior to the remainder of the genitalia. We also describe a new congener infecting the heart of yellowedge grouper, Hyporthodus flavolimbatus (Serranidae), from the Gulf of Mexico. It differs from its congeners by the combination of having an anterior sucker that does not extend beyond the anterior body margin, 2-5 tegumental body spines per row, posterior ceca that are 9 times length of the anterior ceca and that lack any coil, a testis that is 3 times longer than wide and that does not fill the intercecal space, an ovary that is >60% of the body width, a vitelline duct that connects to the anterior aspect of the oötype, a uterus that is >10% of the body width and that extends posterior to all genitalia, and a rounded posterior body margin. It is the first species of Cardicola to be described from a grouper (Serranidae). The 28S and internal transcribed spacer 2 phylogenetic analyses recovered the new species as a distinct lineage within the clade of Cardicola spp.
Cardicola Short, 1953 是最具物种多样性的盾腹属（35 种），包括感染“高鳍鱼类”（真骨总目）的海洋和港湾鱼类血液吸虫。在核糖体 DNA（28S）大亚基的系统发育分析中，盾腹属内的几个分支被回收，但基于核苷酸的分支的形态同源特征仍然难以捉摸。模式种 Cardicola cardiocola (Manter, 1947) Short, 1953 已经 73 年没有被重新采集到，原始描述也不完整；由于其模式种的系统位置不明确，因此对属进行修订具有挑战性。本文通过使用模式标本（USNM 1337732）和从模式宿主——鲈形目（Sparidae）的大头鲈——中采集的新标本，重新描述了 C. cardiocola。它与同属的其他种的区别在于身体长度是宽度的 5 倍，前吸盘有同心的刺列，每列有 2-6 个体棘，食管腺占食管长度的 22-43%，睾丸长度是宽度的 3-5 倍，填满了中肠间的空间，卵黄管与卵型的前侧连接，上行子宫没有任何卷曲，下行子宫产生一个卷曲，明显的阴茎囊通过收缩与精囊分开，围绕阴茎囊末端的体棘突起，以及位于生殖器官其余部分之后的雄性生殖孔。我们还描述了一种新的同属种，感染墨西哥湾黄边石斑鱼（Hyporthodus flavolimbatus）的心脏。它与同属的其他种的区别在于，前吸盘不超过身体前缘，每列有 2-5 个体棘，后盲囊是前盲囊的 9 倍长，没有任何卷曲，睾丸长度是宽度的 3 倍，没有填满中肠间的空间，卵巢宽度超过 60%，卵黄管与卵型的前侧连接，子宫宽度超过 10%，延伸到所有生殖器官的后方，后端呈圆形。这是第一个从石斑鱼（ Serranidae）中描述的 Cardicola 物种。28S 和内部转录间隔区 2 的系统发育分析将新种回收为盾腹属种群内的一个独特谱系。
