GENERIC CONCEPTS IN CLYTEMNESTRIDAE 



Goniopsyllus Brady, 1883 



Brady (1883) established this genus for a single specimen found in 

 a tow-net gathering taken off the Argentinean coast during the 

 voyage of the H.M.S. Challenger. He regarded Goniopsyllus rostratus 

 as most closely related to the harpacticoid genera Enhydrosoma 

 Boeck and Cletodes Brady despite the marked differences in the 

 mouthparts. In addition, Brady remarked on the similarity in swim- 

 ming leg morphology with Peltidium and recognized a certain 

 affinity with the Sapphirinidae because of the rudimentary structure 

 of the mouthparts. The description of G. rostratus is fragmentary 

 and partly inadequate. Brady (1883) failed to observe the mandible. 



Sapphir Car, 1890 



Car ( 1 890) described both sexes of Sapphir rostratus from plankton 

 samples taken off Trieste in the Adriatic. He used and revised 

 Brady's ( 1 878) classification, dividing the free-living copepods in 6 

 families (Calanidae, Cyclopidae, Harpactidae, Peltididae, 

 Corycaeidae and Sapphirinidae), but was apparently unaware of 

 Brady's (1883) later paper describing the closely related Goniopsyllus 

 rostratus. Car ( 1 890) placed Sapphir in the Sapphirinidae merely by 

 way of elimination and excluded the genus from the two harpacticoid 

 families known at that time (Harpactidae, Peltididae) by virtue of the 

 absence of (1) geniculate setae on the antennae, (2) a palp on the 

 mandible and maxillule, (3) modifications of the PI, and (4) a 

 foliaceous P5. Allocation to the Sapphirinidae was substantiated by 

 the dorsoventrally depressed body, the 6-segmented antennules 

 which are similar in both sexes (Car did not recognize the sexual 

 dimorphism and male geniculation), the antenna lacking a defined 

 exopod and geniculate setae on the endopod, the reduced mouthparts, 

 the sexually dimorphic maxillipeds and the small P5. 



In a short note Dahl (1890) considered S. rostratus a junior 

 subjective synonym of G. rostratus but gave no justification for this 

 course of action. 



Car (1891a) admitted that he had overlooked Brady's (1883) 

 Challenger report describing G. rostratus but maintained the dis- 

 tinction between both genera. His conviction was based on three 

 doubtful observations made by Brady ( 1 883): ( 1 ) his statement that 

 all four swimming legs were 'nearly alike' having 3-segmented 

 rami; Brady only figured the P2 which he labelled 'One of the 

 swimming feet', (2) the maxillipeds which were described and 

 figured as 3-segmented, and (3) the 3-segmented fifth legs. Car 

 pointed out that in Sapphir the PI exopod was clearly 1 -segmented, 

 and both the maxillipeds and the P5 2-segmented, but did not 

 consider the possibility that this incongruity could be based on 

 observational errors made by Brady. It was largely this failure that 

 initiated the subsequent dispute between Car and Claus. 



Goniopelte Claus, 1891a 



Both sexes of Goniopelte gracilis were described in remarkable 

 detail by Claus (1891a) on the basis of scanty material (1 9 and \S) 

 collected from an unspecified locality in the Eastern Mediterranean. 

 He recognized the male geniculation ( 'elastischen Cuticularapparaf ) 

 and the 'accessory' aesthetascs of the antennules, the sexual dimor- 

 phism of the caudal rami and the presence of the male P6. Claus also 

 revealed details of the internal anatomy such as the tripartite nauplius 

 eye, the asymmetry of the male genital system and the presence of 

 integumental glands around the rostrum and the pleural areas of the 

 cephalothorax, pedigerous somites and abdomen. 



Claus (1891a) severely criticized the quality of both Brady's 

 ( 1 883) and Car 's ( 1 890) descriptions and like Dahl ( 1 890) professed 

 that G. rostratus and 5. rostratus were not only congeneric but also 



conspecific. The differentiating characters used by Car ( 1 890, 1 89 la) 

 he regarded as irrelevant to the issue. He presented convincing 

 arguments showing that Brady's holotype of G. rostratus could not 

 possibly have been a male. Claus was also the first author to 

 reconsider Dana's Clytemnestra scutellata. He placed the species 

 with reservations in the Scutellidiinae ('Scutellidinen'), a subfamily 

 of the Peltidiidae ('Peltididen'), despite similarities in general body 

 shape and maxilliped structure with his new genus and species 

 Goniopelte gracilis. 



Claus (1891a) remarked that the moderate flattening of the body, 

 the reduction of the mandible and maxillule, and the 1 -segmented P 1 

 exopod in G. gracilis would probably warrant the erection of a third 

 subfamily within the Peltidiidae. An alternative option suggested by 

 Claus was to regard it as a transitionary group between the Peltidiidae 

 and Harpacticidae. 



Car's ( 1 89 1 b) re-examination of S. rostratus did not disclose new 

 information apart from the confirmation of the 4-segmented con- 

 dition of the antenna. Although his rebuttal was mainly aimed at 

 showing disapproval of Claus' (1891a) provocative paper, it con- 

 tained clear indications of the author's ambivalence about both the 

 conspecificity and familial placement of S. rostratus. Car main- 

 tained the latter as a valid genus and species but did not exclude 

 potential synonymy with G. rostratus. He kept the genus in the 

 Sapphirinidae but pointed out the close relationship between Sapphir, 

 Goniopsyllus and Goniopelte and the possible option of proposing a 

 new family for these three genera. Finally, he disagreed with Claus 

 (1891a) on the sexual identity of the holotype of G. rostratus, using 

 the unconfirmed presence of an internal spermatophore in Brady's 

 (1883) habitus drawings as the only counterargument. 



A breakthrough in unravelling the intricate synonymy was realized 

 by Poppe who had already recognized the identity between 

 Clytemnestra and Goniopsyllus in 1 884 but did not publish his results 

 until 1 89 1 . Poppe's ( 1 89 1 ) comprehensive paper, which downgraded 

 Goniopsyllus and Sapphir to junior synonyms of Clytemnestra, was 

 based on a wide range of specimens including the holotype of G. ros- 

 tratus and a male of S. rostratus from Car's collection. He described 

 a new species, Clytemnestra hendorffi from material collected in the 

 Java Sea, the Indian Ocean (south of Madagascar, Western Australian 

 Basin) and the South Atlantic (off Brazil and Argentina). Poppe 

 ( 1 89 1 ) also re-examined Thompson's (1888) material of G. rostratus 

 from Malta and identified it as C. hendorffi. Among the material from 

 the Java Sea he discovered a variety quinquesetosa which differed 

 from the typical form in the longer P5 which carried only 5 setae on 

 the exopod, a more stocky abdomen in both sexes and the caudal rami 

 which were relatively wider proximally. 



Poppe (1891) synonymised G. rostratus and S. rostratus and 

 considered the previous distinction between them to be based on 

 erroneous observations of the P5 by both Brady and Car, and the fact 

 that Brady had misidentified the holotype of S. rostratus as a male 

 and overlooked the PI exopod in this species. For some unknown 

 reason he suspected the latter to be 2-segmented in G. rostratus. He 

 considered only 3 species as valid, all of which he placed in 

 Clytemnestra: C. scutellata, C. hendorffi and C. rostrata (Brady). 

 Poppe further regarded the inadequately described C. tenuis as a 

 probable synonym of C. scutellata and excluded Lubbock's second 

 species C atlantica from the genus on account of the different body 

 shape and the structure of the antennules. 



Poppe (1891) did not accept Car's (1890, 1891a-o) placement in 

 the Sapphirinidae and created a new family Pseudo-Peltididae which 

 showed similarities with the Peltidiidae but differed in the morphol- 

 ogy of the PI (exopod not prehensile and 2-segmented (!) according 

 to Poppe's diagnosis), the absence of a well defined antennary 

 exopod and strongly reduced mouthparts. 



