Abstract Two species of haplochromine cichlid fishes of the genus Diplotaxodon Trewavas, endemic to Lake Malaŵi are described: Diplotaxodon longimaxilla, new species, and Diplotaxodon altus, new species. Diplotaxodon altus is diagnosed from other species in the genus based on body depth (35.1–37.8% SL), number of gill rakers (21–26), and a smaller cheek depth (18.2–20.0% HL). Diplotaxodon longimaxilla is delimited from other Diplotaxodon spp. based on body depth (28.9–32.4% SL), horizontal eye diameter (HED 27.1–32.1% HL), smaller cheek depth (15.2–19.4% HL), and number of lateral-line scales (35–38). Other authors have indicated that several other Diplotaxodon spp. occur, but too few specimens were available to permit detailed comparisons. The two new species occur sympatrically at depths of between 40–130 m. Specimens of Diplotaxodon altus were sampled from nets deployed at night using light attraction, while specimens of D. longimaxilla were sampled from nets operated both at night and day. We further examined the three co-types of Diplotaxodon argenteus, the type species of the genus, and designated a lectotype.

中文翻译：

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描述来自非洲马拉日湖的两种深水鱼类 Diplotaxodon (Teleostei: Cichlidae)

摘要 描述了 Malaŵi 湖特有的 Diplotaxodon Trewavas 属的两种单倍色氨酸慈鲷鱼：Diplotaxodon longimaxilla，新种和 Diplotaxodon altus，新种。Diplotaxodon altus 根据体深 (35.1–37.8% SL)、鳃耙数量 (21–26) 和较小的脸颊深度 (18.2–20.0% HL) 从该属的其他物种中诊断出来。Diplotaxodon longimaxilla 与其他 Diplotaxodon spp 分开。基于身体深度 (28.9–32.4% SL)、水平眼睛直径 (HED 27.1–32.1% HL)、较小的脸颊深度 (15.2–19.4% HL) 和侧线鳞片的数量 (35–38)。其他作者指出，其他几种 Diplotaxodon spp。发生，但样本太少，无法进行详细比较。这两个新种同域出现在 40-130 m 之间的深度。Diplotaxodon altus 的样本是从夜间使用光吸引部署的网中采样的，而 D. longimaxilla 的样本是从夜间和白天操作的网中采样的。我们进一步检查了 Diplotaxodon argenteus 的三个共同类型，该属的模式种，并指定了一个选型。