Department of Biology, Ramkhamhaeng University, Bangkok 10240, Thailand. .
Department of Biology, Bansomdejchaopraya Rajabhat University, Bangkok 10600, Thailand. .
Zootaxa. 2021 Oct 12;5051(1):41-67. doi: 10.11646/zootaxa.5051.1.6.
Two new species of the family Harpacticidae Dana, 1846, Tigriopus namsaiensis sp. nov. and T. wannapaensis sp. nov. were found in algal washings at Namsai and Wannapa beaches in Chonburi Province, Thailand. There are currently 14 known species in the genus, two of which, T. thailandensis Chullasorn, Ivanenko, Dahms, Kangtia Yang, 2012 and T. sirindhornae Chullasorn, Dahms Klangsin, 2013 were also discovered in Thailand. The genus Tigriopus Norman, 1869 has a worldwide distribution with nine species recorded from the Pacific Ocean (seven in the North Pacific and two in the South Pacific), four species from the Atlantic and adjacent seas, two species from the South Indian Ocean, and one species from Antarctica. Sexual dimorphism is expressed in the antennule, antenna, P2, P5, P6, and segmentation of the urosome. Tigriopus namsaiensis sp. nov. and T. wannapaensis sp. nov. are closely related to T. thailandensis and T. sirindhornae in sharing the following characters: fewer sensilla on the prosome; antennary exopod with one seta on exp-2; P4 exp-3 with two inner setae; female P5 baseoendopod with five setae; male P2 enp-2 with a seta fused to the segment; and male P5 exopod with five setae. Tigriopus namsaiensis sp. nov. closely resembles T. thailandensis, but the new species is characterized by four setae on the maxillulary coxa (three setae in T. thailandensis), the outermost seta on the female P6 is plumose (instead of the middle one), the lateral seta on the apical segment of the antennary exopod is discrete at the base (instead of fused to the segment), and the outermost seta of the male P5 exopod is plumose (instead of spinulose). Tigriopus wannapaensis sp. nov. is very closely related to T. sirindhornae, but the new species differs from the latter by the following characteristics: 2-segmented mandibular exopod (3-segmented in T. sirindhornae); five setae on the maxillulary coxa (instead of three); all setae on female P6 are plumose (instead of two plumose and one pinnate); the lateral seta on the apical segment of the antennary exopod is fused to the segment (instead of discrete at the base); and the outermost seta on the male P5 exopod is plumose (instead of spinulose). A dichotomous identification key to the 16 valid species of Tigriopus is provided.
在泰国春武里府 Namsai 和 Wannapa 海滩的藻类冲洗物中发现了两种 Dana 1846 年的 Harpacticidae 科新种，即 Tigriopus namsaiensis sp. nov. 和 T. wannapaensis sp. nov.。目前该属已知有 14 种，其中两种，即 T. thailandensis Chullasorn、Ivanenko、Dahms、Kangtia Yang，2012 年和 T. sirindhornae Chullasorn、Dahms Klangsin，2013 年也在泰国发现。Tigriopus Norman，1869 属在全球范围内分布，有 9 种记录于太平洋（北太平洋 7 种，南太平洋 2 种）、大西洋及毗邻海域 4 种、南印度洋 2 种、南极洲 1 种。性二态性表现在触角、触角、P2、P5、P6 和尾节的分段上。Tigriopus namsaiensis sp. nov. 和 T. wannapaensis sp. nov. 与 T. thailandensis 和 T. sirindhornae 密切相关，它们具有以下共同特征：前体上的感觉器官较少；触角外肢上 exp-2 上有一根刚毛；P4 exp-3 有两根内刚毛；雌性 P5 基内叶有五根刚毛；雄性 P2 enp-2 上有一根与节融合的刚毛；雄性 P5 外肢有五根刚毛。Tigriopus namsaiensis sp. nov. 与 T. thailandensis 非常相似，但新种的特点是在 maxillulary coxa 上有四根刚毛（T. thailandensis 上有三根刚毛），雌性 P6 的最外侧刚毛是羽状的（而不是中间的），触角外肢的顶端节上的侧刚毛在基部是离散的（而不是与节融合的），雄性 P5 外肢的最外侧刚毛是羽状的（而不是刺状的）。Tigriopus wannapaensis sp. nov. 与 T. sirindhornae 非常相似，但与后者不同的是：下颌外肢 2 节（T. sirindhornae 为 3 节）；maxillulary coxa 上有五根刚毛（而不是三根）；雌性 P6 的所有刚毛都是羽状的（而不是两根羽状和一根羽状）；触角外肢的顶端节上的侧刚毛与节融合（而不是在基部离散）；雄性 P5 外肢的最外侧刚毛是羽状的（而不是刺状的）。提供了 16 种有效 Tigriopus 种的二分法鉴定关键。
