Podosiridae, a new family of North Atlantic deep sea amphipod (Crustacea, Amphipoda)
Podosiridae, a new family of North Atlantic deep sea amphipod (Crustacea, Amphipoda)
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Podosiridae，北大西洋深海片脚类新科（甲壳纲，片脚类）
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
A. Myers
中科院分区：
文献类型：
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作者：
J. Lowry;A. Myers
Bellan-Santini(2007)描述了亚速尔群岛三重交界区中大西洋海脊上的一个喷口群落中的Podosius vaderi。当时，她把它归入Eusiridae家族，并指出了它与Podoceridae的相似之处。最初对瓦德雷的描述是基于一只多产的雌性。雄性特征尚不清楚，但根据在尾足类1和2上类似的双足类中没有顶端粗壮刚毛的既定趋势，可以推测存在最小的性别二型性。因为雌性的第一节足目动物比第二节节肢动物小，而第二节节肢动物又发育得很好，所以雄性节肢动物很可能会有类似的节肢动物。男性是否会发生钙化也不得而知。Bellan-Santini(2007)最初将Podosius vaderi归入Eusiridae复合科(由Barnard&Karaman于1991年定义)。Bousfield和Hendrycks(1995,1997)不接受这种家庭安排，他们重新建立了Eusiridae，Calliopiidae和Pontogeneiidae三个科。从Barnard&Karaman(1991)或Bousfield&Hendrycks(1995)的意义上讲，瓦氏江豚不是真的，因为：上颌骨2在内板上没有斜毛排，比外板短得多；所有的髋骨大小相似；在髋骨5上没有裂片；在沸石1-3上有背隆突；尾体1细长；端部全缘。同样地，它也不是骨瓣科，因为它的身体是近圆柱形的；上颌骨2内板比外板短得多；髋骨大小相似，腹足5臀足没有裂片；腹足3-4节是线形的，远长于足头；腹足5-7底是线形的；尾足1-2没有顶端粗壮的刚毛，尾足3有花柱状分支。尾足1-2支没有顶端粗壮的刚毛，尾足3支为花柱状，尾足3支为全缘。Vaderi Podosius vaderi实际上与双足类最相似(Fig.1)。它们有许多共同的核心特征，例如：形状相似的头部，特别是头侧小叶和前腹角；长的下颌瓣具拉长的第三文章；长的上足瓣具刺状的指骨；亚圆柱形的身体；节足1和2近螯合；周足类5-7具基本线形；具隆突背部的复叶。两组均可见伸长的弧形贝足类。尿体1在两个分类群中都是细长的，但在Podosirus中较长。Vaderi Podosius vaderi与Amathillopsidae共有以下一组诊断特征：Coxa 1小于Coxa 2，周足节5-7，背隆突，尾足3外支长度近等长，有柄，端部全缘。然而，由于下列显著差异：副鞭毛不存在；节足1腕长于前足；节足1小于节足2；无尾尖；尾节4和5大小相等，尾节1伸长。该家族的波多西里亚科。11月因此在这里为Podosius Vaderi Bellan-Santini竖立。
Bellan-Santini (2007) described Podosirus vaderi from a vent community on the Mid-Atlantic Ridge in the Azores Triple junction zone. At the time she placed it in the family Eusiridae and pointed out similarities to the Podoceridae. The original description of Podosirus vaderi was based on an ovigerous female. Male characteristics are not known, but based on established trends among similar amphipods without apical robust setae on uropods 1 and 2, it is presumed that there is minimal sexual dimorphism. Because the female has the first gnathopod smaller than the second and a well developed male-like second gnathopod, it is probable that the male will have similar gnathopods. Whether calceoli occur in the male is also not known. Bellan-Santini (2007) originally placed Podosirus vaderi in the composite Eusiridae (as defined by Barnard & Karaman 1991). This family arrangement was not accepted by Bousfield & Hendrycks (1995, 1997) who re-established the original families Eusiridae, Calliopiidae and Pontogeneiidae. In the sense of Barnard & Karaman (1991) or Bousfield & Hendrycks (1995) Podosirus vaderi is not a eusirid because: maxilla 2 is without an oblique setal row on the inner plate which is much shorter than the outer plate; all coxae are similar in size; there are no lobes on coxa 5; there are dorsal carinae on pereonites 1–3; urosomite 1 is elongate; and the telson is entire. Likewise it is not a calliopiid because the body is subcylindrical; maxilla 2 inner plate is much shorter than the outer plate; coxae are all similar in size and pereopod 5coxa iswithout lobes; pereopods 3–4 merus is linear and much longer than the propodus; pereopods 5–7 basis is linear; uropods 1–2 are without apical robust setae and uropod 3 has styliform rami. It is not a pontogeneiid because all coxae are about the same size; carinae occur on the pleonites; there are no apical robust setae on the rami of uropods 1–2; uropod 3 rami are styliform; and the telson is entire. Podosirus vaderi is in fact most similar to amathillopsid amphipods (fig. 1). They share many core characters such as: similarly shaped heads, particularly the lateral cephalic lobes and the anteroventral corners; long mandibular palps with elongate third articles; long maxillipedal palps with stabbing dactyli; subcylindrical bodies; gnathopods 1 and 2 subchelate; pereopods 5–7 with basis linear; pleonites with dorsal carinae. The curved pereopods with elongate meri occur in both groups. Urosomite 1 is elongate in both taxa, but longer in Podosirus. Podosirus vaderi shares the following group of diagnostic character states with the Amathillopsidae: coxa 1 smaller than coxa 2, pereopods 5–7 of equal length, pleon with dorsal carina, uropod 3 outer ramus subequal in length with peduncle, telson entire. Podosirus cannot be placed within the Amathillopsidae, however, because of the following significant differences: accessory flagellum absent; gnathopod 1 carpus longer than propodus; gnathopod 1 smaller than gnathopod 2; no coxae acuminate; coxa 4 and 5 subequal in size and urosomite 1 elongate. The family Podosiridae fam. nov. is therefore erected here for Podosirus vaderi Bellan-Santini.