Institute of Parasitic Diseases, 11445 East Via Linda 2-419, Scottsdale, Arizona 85259.
Department of Biology, Brigham Young University, 1114 MLBM, Provo, Utah 84602.
J Parasitol. 2021 Mar 1;107(2):222-238. doi: 10.1645/20-126.
A new archiacanthocephalan in the family Gigantorhynchidae, Intraproboscis sanghae n. gen., n. sp. is described from females collected from the African black-bellied pangolin Phataginus tetradactyla Linn. (Manidae) in the Central African Republic. A dichotomous key to the genera of Gigantorhynchidae is provided. The specimens presented are distinct from those of the genus Gigantorhynchus Hamann, 1892 that have only 1 or 2 circles of hooks (crowns) at the apical end of the proboscis and are found in South American mammals, except for Gigantorhynchus pesteri Tadros, 1966 from baboons in Rhodesia (Zimbabwe), Africa (Amin, 2013). They superficially resemble those of the other gigantorhynchid genus Mediorhynchus Van Cleave, 1916, especially in the organization of the truncate-cone proboscis and the position of the receptacle. Species of Mediorhynchus are bird parasites. The new genus, Intraproboscis, now the third genus in Gigantorhynchidae; however, is distinguished from Mediorhynchus by having a simple proboscis receptacle that is completely suspended within the proboscis, the passage of the retractor muscles through the receptacle into the body cavity posteriorly, absence of neck, and presence of a parareceptacle structure (first finding in the Archiacanthocephala) and a uterine vesicle; among other features, including the differential dorsoventral thickness of the body wall. The receptacle in Mediorhynchus is complex, with many accessory muscles and retractor muscles passing into the body cavity dorsally and ventrally. Our specimens reached 180 mm in length and the proboscis had 34-36 rows of 6-7 ventrally lamellated, rooted hooks each anteriorly, and 15-17 spinelike hooks each posteriorly. Micropores extended into the anterior and posterior proboscis and energy dispersive x-ray analysis (EDXA) of anterior hooks showed high levels of calcium and phosphorus but negligible traces of sulfur. Spinelike hooks in the posterior proboscis had lower levels of Ca and P and slightly higher levels of S. Molecular and phylogenetic analyses based on the 18S rDNA gene placed I. sanghae in a clade with the archiacanthocephalans Mediorhynchus, Moniliformis, Macracanthorhynchus, Oncicola, and Oligacanthorhynchus.
一种新的巨吻棘头虫科（Gigantorhynchidae），名为 Intraproboscis sanghae n. gen., n. sp.，是从非洲黑腹穿山甲（Phataginus tetradactyla Linn.）（穿山甲科）中采集到的雌性个体中描述的。提供了一个巨吻棘头虫科属的二分检索表。所呈现的标本与仅在吻的顶端有 1 或 2 圈钩（冠）的属 Gigantorhynchus Hamann，1892 不同，该属发现于南美洲的哺乳动物中，但 Gigantorhynchus pesteri Tadros，1966 除外，它来自非洲罗得西亚（津巴布韦）的狒狒（Amin，2013）。它们在外观上与其他巨吻棘头虫属 Mediorhynchus Van Cleave，1916 非常相似，尤其是在截锥形吻和接受器的位置上。Mediorhynchus 物种是鸟类寄生虫。新属 Intraproboscis 现在是 Gigantorhynchidae 的第三个属；然而，它与 Mediorhynchus 的区别在于，它具有一个简单的吻接受器，该接受器完全悬挂在吻内，牵引肌通过接受器向后进入体腔，没有颈部，并且存在副接受器结构（在 Archiacanthocephala 中首次发现）和子宫囊；还有其他特征，包括体壁的背腹厚度差异。Mediorhynchus 的接受器很复杂，有许多附属肌肉和牵引肌向前和向后进入体腔。我们的标本长度达到 180 毫米，吻部有 34-36 排，每排有 6-7 个向腹侧分层的、有根的钩，每排有 15-17 个刺状钩。微孔延伸到吻的前、后部分，前钩的能谱 X 射线分析（EDXA）显示高钙和磷水平，但硫痕量可忽略不计。后吻部的刺状钩的 Ca 和 P 水平较低，S 水平略高。基于 18S rDNA 基因的分子和系统发育分析将 I. sanghae 置于与巨吻棘头虫属 Mediorhynchus、Moniliformis、Macracanthorhynchus、Oncicola 和 Oligacanthorhynchus 亲缘关系密切的分支中。
