FRESHWATER NEMATODES FROM LOCH NESS 



13 



most part with the original description. Minor differences include 

 slightly lower values for tail length, tail/V-a and ratio c'. These 

 measurements however, fall within the range of measurements of 

 females of M. bryophilus examined by Brzeski (pers. comm.). 



Malenchus pachycephalia Andrassy, 1981 



(Fig. 16) 



Material examined. Foyers Plateau: 157 m; core 16. 1 9. 



Female, (n = 1). L = 497 pm; a = 20; b = 4.9; c = 6.1; c'= 7.0: V 

 = 69; V ' = 8 1 .6; tail/V-a = 1 .0; tail = 8 1 .2 pm. 



Head slightly offset, 6.4 pm wide at base with 4-5 fine annules. 

 Amphids not evident. Annules 2.1 pm wide at mid-body. Lateral 

 field with two lines appearing smooth or strongly crenate depending 

 on fine focus; originating at 3 annules or 4.0 pm anterior to spear 

 knobs; terminating at about 46% of tail length. Spear 12 pm long 

 with knobs about 2.4 pm wide. Excretory pore 93 pm from anterior, 

 almost at level of posterior margin of basal bulb. Oesophagus 100 

 pm long; median bulb slender ovoid; valve hardly evident located at 

 44% of oesophageal length. Phasmid like structure not seen. Ante- 

 rior genital branch 170 pm long. Spermatheca bilobed 24 pm long 

 with rounded sperms about 1.3 pm in diameter. Postuterine sac 9.6 

 pm long. Vagina slightly tilted anteriorly with thickened walls. 

 Vulva - anus distance 76.8 pm. Tail tip tapering to a fine point. 



Distribution and habitat. Recorded from USA, Spain, Hun- 

 gary and Bulgaria; occurs in soil around plant roots. 



Remarks. Using the keys of Andrassy (1981) and Geraert & 

 Raski (1986), this specimen can be identified as M. pachycephalias, 

 but the anterior part of the oesophagus is not distinctly longer lhan 

 the posterior as described in the original description, however, this 

 feature is not evident in the accompanying illustration of the anterior 

 end (Andrassy. 1981: Fig. 13c). It also differs in having a longer tail 

 81 pm v.v (56-72); this range includes measurements from the 

 original description and a Spanish population (Gomez Barcina etui., 

 1992). 



Malenchus pressulus (Kazachenko, 1975) Andrassy, 1981 



(Fig. 17) 



MATERIAL EXAMINED. Deep South Basin: 204 m; core 9. 1 9. 



V 



Female. (n=l). L = 460pm;a = 25;b = 5.l:c = 5.9;c' = 8 

 = 66.9; V = 80.5; tail/V-a = 0.95; tail = 77.7. 



Head not offset, 7.0 pm wide at base with 3-4 minute annules at 

 focal level of dorso-ventral margin, otherwise appearing smooth by 

 light microscopy. Amphids sinuous. Annules 1.5 pm at mid body. 

 Lateral fields with two lines appearing smooth or crenate depending 

 on fine focus; originating at level of spear knobs, terminating at 

 about 32% of tail length. Spear delicate, 11.8 pm long with spear 

 knobs 2.5 pm wide. Excretory pore 86 pm from anterior at level of 

 posterior margin of basal bulb. Oesophagus 89 pm long; median 

 bulb slender ovoid, valve not evident; centre of median bulb located 

 at about 51% of oesophageal length. Phasmid like structure located 

 at 1 4 annules anterior to vulva. Anterior genital branch 1 70 pm long. 

 Spermatheca elongate ovoid, 19 pm long with indistinct rounded 

 sperms about 1.3 pm in diameter. Postuterine sac 12.8 pm long. 

 Vagina slightly tilted anteriorly, with thickened walls. Vulva slightly 

 sunken. Vulva - anus distance 74.5 pm. Tail tip pointed. 



Distribution and habitat. Originally described from Russia in 

 soil of a coniferous forest with an additional record from soil around 

 grass roots (Andrassy, 1981). 



Fig. 17 Malenchus pressulus (Kazachenko. 1975). A-D. female. A. 

 oesophageal region; B. posterior end of reproductive system; C, tail: D. 

 habitus. Scale bars a = 20pm, b = 100 pm. 



REMARKS. This single female largely agrees with the redescription 

 of M. pressulus by Andrassy (1981 ) minor differences in ratios c, c' 

 and tail/V-a are not considered to be of specific importance. 



Miculenchus salvus Andrassy, 1959 



MATERIAL EXAMINED. Fort August Bay: 91, 92, 98 m; cores 2, 4, 

 5. 3 99. 1 6. Deep South Basin: 1 97 in; core 1 2, 2 99. Foyers Plateau: 

 157-160 m; cores 14-16. 18.699, Id. 



Remarks. These specimens were described and figured by Wanless 

 & David (1997). 



Tylenchus rex Andrassy, 1979 



(Figs 18, 36D) 



MATERIAL examined. Deep South Basin: 194 m; core 13, 1 6. 



Male, (n = 1). L = 974 pm; a = 36.3; b = 6.3; c = 6.1; c' = 9.0; 

 gubernaculum = 5.9 pm; spicules = 24 pm; tail = 160 pm. 



Head 8.5 pm at base with 4-5 annules. Amphid opening a gently 

 curved slit. Annules distinct about 2. 1 pm at mid-body. Lateral field 

 with four lines, outers weakly crenate. Spear robust, 20.5 pm long, 

 with large basal knobs 3.5 pm wide. Excretory pore 130 pm from 

 anterior. Oesophagus 154 pm long; median bulb ovoid, valves 

 distinct at 47.5% of oesophageal length. Testis 262 pm long occupy- 

 ing 27% of body length. Bursa adanal about 38 pm long with 

 crenated margins. Anterior margin of cloacal lips with two spicate 

 projections (arrowed, fig.36D). Tail tip rounded. 



DISTRIBUTION AND HABITAT. The type population was found in 

 moss, Ben Hedi, Scotland. Also known from Poland and Australia. 



REMARKS. This specimen largely agrees with the original descrip- 

 tion except that the basal bulb is more or less elongate rather than 

 pyriform; the outer lateral lines of the lateral field are weakly crenate 



