CAN. J. ZOOL. VOL. 57, 1979 The karyology of Procerodes lobata (Turbellaria, Tricladida, Maricola) IAN R. BALL Drprrrtmrnt ofBiology, Uniui,,:sitv of Wrrterloo, Ont., Crrnrrrlm trnd lnstilurc~ of T~xono~nii. Zoology, Unicrrsitv of Atn.stc,r.dtr~n, Postbus 20125, 1000 HC Amsterdrm, The Netherlands Received February 19, 1979 BALL.. I. R. 1979. The karyology of Procerodc~s lohata (Turbellaria, Tricladida, Maricola). Can. J. Zool. 57: 1820-1821. The diploid complement of the marine planarian Proc,rrodr.s lobatir, collected from the type locality, Corfu, consists of 14 metacentric chromosomes. The karyotype is virtually identical with that of P. littorolis, the only other member of the genus for which detailed karyometric data are available, but it differs from British populations of P. lobara. Early records of P. lohafa in North America probably refer to Uteriporus uulgaris, a species whose occurrence in eastern Canada has recently been established. The two species are almost indistinguishable in life but they may be separated karyologically, even when immature. BALL. I. R. 1979. The karyology of Proci.rodes loharrr (Turbellaria, Tricladida, Maricola). Can. J. Zool. 57: 1820-1821. Le complement chromosomique diplo'ide du turbellarie marin Procerodes lobatu provenant de la localite-type, Corfou, consiste en 14 chromosomes metacentriques. Ce caryotype est a peu pres identique a celui de P. littoralis, la seule autre espece du genre dont la cariologie soit connue; le caryotype de P. lobatrr de Corfou diffkre cependant de celui des populations britanniques deP. lohotrr. Les premiers P. lobatu trouves en Amerique du Nord sont probablement des Uteriporus uulgaris, espece dont la presence dans I'Est du Canada est reconnue depuis peu. Les deux especes sont peu pres impossibles a distinguer par leur morphologie externe, mais leurs caryologies respectives permettent de les reconnaitre, meme aux stades imrnatures. [Traduit par le journal] Introduction Results The value of karyological data for the under- standing of the evolutionary relationships of aqua- tic planarians is well established (Benazzi and Benazzi-Lentati 1976). Almost all of the pertinent data have been obtained from the freshwater species and hitherto only six members of the Maricola have been studied. Detailed karyometric data are available for only three of these species (Ball 1976). This note presents findings from the Mediterranean species, Procerodes lobata, col- lected from near the type locality in Corfu, Greece. Studies on freshwater species from the same island have been reported elsewhere (Ball 1978). A brief assessment of records of this species from North In all the metaphase plates examined 14 chromo- somes were counted. It was easy to recognize which chromosomes were members of pairs and there is no doubt that the haploid number is seven. Oogenesis was not studied but spermatogenesis appeared normal, with the formation of seven bi- valent~. The relative lengths and centromeric indices of the seven chromosome pairs are shown in Table 1 and these form the basis for the idiogram (Fig. 1). It is clear that all the chromosomes are metacentric and, with the exception of element 1, fairly uniform with respect to relative length and centromeric index. In the first pair of chromosomes the propor- America is also given. tions were rather variable. Materials and Methods Discussion Specimens ofProcerode~ lobatu were collected in abundance what little is known of the karyology of marine at numerous sites on the east coast of Corfu from Corfu town to Messonghi Beach in May 1978. They were found on the under- planarian~ has been reviewed earlier all 1976), side of stones at. or iust above. the waterline. Manv soecimens and further observations have been made by Gal- < . were reserved on site and later seriallv sectioned to confirm leni and Puccinelli 11975. 1977). The karvotv~e of . their identity. The majority were transported to the laboratory in pyoceyodeslobata from the type locality is virtually Amsterdam and cultured there for karyological study. The data identical with that of the widespread species pro- presented are for specimens from the beach at Benitses; all populations studied were identical karyologically. The methods ceyodes littorulis (cf. Fig. 1 with Ball 19767 Fig. 1). of study and analysis were as previously described (Ball 1976). This IS further corroboration of the belief that the 0008-4301/79/091820-O2$01 .OO/O @I979 National Research Council of Canada/Conseil national de recherches du Canada Can. J. Zool. Downloaded from www.nrcresearchpress.com by McMaster University on 11/25/14 For personal use only.