Willenz Philippe, Ereskovsky Alexander V, Lavrov Dennis V
Royal Belgian Institute of Natural Sciences, Taxonomy and Phylogeny, Rue Vautier 29, B-1000, Bruxelles, Belgium Université Libre de Bruxelles, Laboratoire de Biologie Marine, Avenue F.D. Roosevelt 50, B-1050, Bruxelles, Belgium.
Zootaxa. 2016 Dec 21;4208(6):zootaxa.4208.6.1. doi: 10.11646/zootaxa.4208.6.1.
A series of recent expeditions in fjords and canals of Southern Chilean Patagonia allowed the re-collection of Halisarca magellanica Topsent, 1901 and the discovery of a new species, Halisarca desqueyrouxae sp. nov. The material studied was collected at depths ranging from 3 to 30 m at latitudes comprised between 42° and 49°S. Both species share the same habitat and show a morphological plasticity, but differ in their colour. Halisarca magellanica is bright pink to whitish with three morphs whereas H. desqueyrouxae sp. nov. is light brown to beige with two morphs. An extensive investigation in TEM and SEM reveals several differences among cell types with inclusions between both species. Three distinct spherulous cells occur. Type 1 is shared by both species, Type 2 is occasional in H. magellanica but absent from H. desqueyrouxae sp. nov. Type 3 is rare in H. magellanica and occurs abundantly in half of the specimens of H. desqueyrouxae sp. nov. Granular cells are shared by both species but do not occur in all specimens. Microgranular cells are characteristic of H. magellanica. Both species also clearly differ by their endobiotic bacteria. Phylogenetic analysis of cox1 sequences places H. magellanica as a sister group to all other previously published Halisarca species sequences (9.1-9.7% difference) except H. harmelini, while H. desqueyrouxae sp. nov. is placed as a sister group to H. dujardini (2.3% difference).
最近在智利南部巴塔哥尼亚的峡湾和运河进行的一系列考察，使得1901年的麦哲伦海绵（Halisarca magellanica Topsent）得以重新采集，并发现了一个新物种——德氏海绵（Halisarca desqueyrouxae sp. nov.）。所研究的材料是在南纬42°至49°之间、深度为3至30米的海域采集的。这两个物种共享相同的栖息地，且表现出形态可塑性，但在颜色上有所不同。麦哲伦海绵呈亮粉色至白色，有三种形态，而德氏海绵新物种呈浅棕色至米色，有两种形态。通过透射电子显微镜（TEM）和扫描电子显微镜（SEM）进行的广泛研究揭示了两种海绵细胞类型及其内含物之间的若干差异。出现了三种不同的球状体细胞。类型1为两个物种所共有，类型2在麦哲伦海绵中偶尔出现，但在德氏海绵新物种中不存在。类型3在麦哲伦海绵中很少见，而在德氏海绵新物种的一半标本中大量出现。颗粒细胞为两个物种所共有，但并非在所有标本中都出现。微颗粒细胞是麦哲伦海绵的特征。这两个物种在其内生细菌方面也有明显差异。对细胞色素氧化酶亚基1（cox1）序列的系统发育分析表明，麦哲伦海绵是除哈梅林海绵（H. harmelini）之外所有其他先前发表的海绵物种序列的姐妹群（差异为9.1 - 9.7%），而德氏海绵新物种是杜氏海绵（H. dujardini）的姐妹群（差异为2.3%）。
