Stockigidiella, Iannilli, Valentina, Holsinger, John R., Ruffo, Sandro & Ronald, 2006

Iannilli, Valentina, Holsinger, John R., Ruffo, Sandro & Ronald, 2006, Two new genera and two new species of the subterranean family Bogidiellidae (Crustacea, Amphipoda) from groundwaters in northern Oman, with notes on the geographic distribution of the family, Zootaxa 1208, pp. 37-56 : 39

Stockigidiella new genus

Diagnosis

A stygomorphic bogidiellid amphipod distinguished by mandibles without molars, gnathopods 1 and 2 subsimilar in size, carpus and propodus of pereopods 5 and 6 with row of long, deeply bifid setae, pleopods without inner rami, and uropods 1 and 2 similar.

Type species

Stockigidiella aequimana new species, by monotypy. Gender is feminine.

Derivatio nominis

It is a distinct pleasure to name this new genus in honour of our late friend and eminent colleague, Prof. Dr. Jan H. Stock of the University of Amsterdam, whose expedition to the Sultanate of Oman and other parts of the world resulted in the collection of many new taxa of subterranean amphipods from biologically poorly known regions.

Remarks

The peculiar characters that collectively distinguish Stockigidiella from the other bogidiellid genera include the absence of a true mandibular molar, subequality of gnathopods 1–2 and the long, apically bifid setae on the carpus and propodus of pereopods 5 and 6. In all previously described bogidiellids the first pair of gnathopods differs from the second pair, especially in the shape of the propodus, which is typically piriform in the first and subtrapezoidal in the second. Whereas, in contrast the propods of both pairs of gnathopods in S tockigidiella are elongate and suboval. The carpal segment of gnathopod 1 in Stockigidiella is also different. In most other bogidiellids the carpal lobe of gnathopod 1 is typically more prominent, and in many it extends along the posterior margin of the propodus, sometimes nearly reaching the defining angle of the palmar margin. However, in Stockigidiella the posterior lobe of the carpus of gnathopod 1 is a relatively poorly developed prolongation not much extended along the posterior margin of the propodus. In comparison, the posterior lobe of the carpus of gnathopod 2 is rounded, not elongate, and similar to that in most other bogidiellids. We believe that the near equality of the gnathopods is a primitive or plesiomorphic character in bogidiellid amphipods, whereas the presence of the deeply bifid setae on the carpus and propodus of pereopods 5 and 6 appears to be a novel or apomorphic character. The latter character was previously unknown, or at least un­recorded, in other genera of bogidiellids. Among all bogidiellids known to date, only the genus Hebraegidiella Karaman (1988) from the shore of the Dead Sea in Palestine shows a moderately close affinity with Stockigidiella . In this genus, the gnathopods are only weakly differentiated and the mandible lacks a triturative molar. However, several other important characters, including presence of inner rami on the pleopods and normal setation of pereopods 5 and 6, separate Hebraegidiella from Stockigidiella .