SEVEN SPECIES OF RED SEA ONCAEA 



27 



species of Oncaea s.str. and erroneously placed it in a group 

 containing O. petila Heron, O. ovalis Shmeleva and others. In the 

 present account, O. waldemari is completely redescribed based on 

 Red Sea specimens (figures) and the type material from Brazilian 

 waters, with additional comparisons on specimens from different 

 localities in the Atlantic and Pacific Ocean. 



MATERIAL AND METHODS 



Oncaeids were collected using a multiple opening-closing net with 

 a mesh size of 0.05 mm during cruise 5/5 of R/V Meteor (Weikert, 

 1988) in various locations of the Red Sea (Fig. 1 ). Samples collected 

 during cruise 29 of R/V Valdivia with the same sampling gear, but 



equipped with nets of 0.1 mm mesh, were also examined. A station 

 list and sampling data are given in Table I. The plankton was initially 

 fixed in a 4% formaldehyde-seawater solution buffered with 

 hexamethylene tetramine and transferred after ca 2 years into a 

 preservation fluid of 5% propylene glycol, 0.5% propylene pheno- 

 xetol, and 94.5% filtered seawater (Steedman, 1976). Specimens 

 were dissected in lactic acid, mounted on slides in lactophenol and 

 sealed with transparent nail-varnish. All figures have been prepared 

 using a camera lucida on a Leitz Dialux differential interference 

 contrast microscope. 



Total body length and the ratio of prosome to urosome (excluding 

 caudal rami) were calculated as the sum of the middorsal lengths of 

 individual somites measured in lateral view. In the case of telescop- 

 ing somites these lengths are measured from the anterior to the 



Table 1 Sampling data of multiple opening-closing net in the Red Sea and adjacent areas (D = Day. N = Night). 



Stn. No. 



Date 



Time 



Total water depth (m) 



Mesh size (mm) 



Geographic position (°N, °E) 



Red Sea + Gulf of Aden 







R/V Valdivia Cruise 29 







130 



28.10.1980 



D 



664 



21.2.1981 



D 



R/V Meteor Cruise 5/5 







63 1 a 



11.7.1987 



N 



663 



20.7.1987 



D 



703 



3.8.1987 



D 



708 



5.8.1987 



D 



Northern Arabian Sea 







R/V Meteor Cruise 32/3 







247 



14.5.1995 



D 



Eastern Mediterranean Sea 







R/V Meteor Cruise 5/1 







35 



20. 1.1987 



N 



1960 

 2000 



1400 

 1200 

 970 

 190 



3000 



3400 



0.1 

 0.1 



0.05 

 0.05 

 0.05 

 0.05 



0.05 



0.05 



21°25.5\ 38°01.9' 

 21°22.r, 38°05.1' 



11 55.5',43°37.9' 

 22°58.4', 37° 19.4' 

 15 34.8',41 54.9' 

 13°40.0'.42°37.4' 



ca 19°.ca65° 



34°25.3'. 26° 14.8' 



30° ■$?: 



20° 



10° [• 

 N 



30' 



20' 



10' 

 N 



30° 



Fig. 1 Location of stations in the Red Sea and adjacent areas. ▲ = Vtf/<7n'/fl-Cruise 29, October 1 980, February 1 98 1 ; ■ = Meteor-Cruise 5/1 , January 

 1987; • = Meteor-Cruise 5/3a, April 1987; T = Meteor-Cruise 5/5, July/August 1987; ♦ = Meteor-Cruise 32/3, May 1995. 



