FRESHWATER NEMATODES FROM LOCH NESS 



19 



Head rounded with truncate anterior end, and minute protrusions 

 at margins of lip region Annules 1.0 pm at mid-body. Lateral field 

 with four lines. Spear 14 pm long with laterally directed knobs 

 3.2pm wide. Dorsal oesophageal opening about 5.0 pm behind 

 spear knobs. Excretory pore 69 pm from anterior. Hemizonid just 

 anterior to excretory pore. Oesophagus 84 pm long, poorly pre- 

 served. Vulva flaps prominent about 5.0 pm long. Vagina curved 

 anteriorly. Anterior genital branch outstretched. Spermatheca not 

 seen. Vulva-anus distance 36.5 pm. Tail tip finely rounded. 



Remarks. Using Raski's (1975) key to, Paratylenchus spp with a 

 spear < 38 pm long, this female comes to either P. italiensis Raski, 

 1975 or P. tateae Wu and Townshend, 1973. Unfortunately these 

 species are difficult to separate from one another because of overlap 

 or continuous sequences in respect of their measurements. Head 

 structures are also remarkably similar. The present female differs 

 slightly in respect of ratios c, V and spear length, also the head is not 

 offset. More specimens are required to assess variation and identify 

 this female with any confidence. 



Aphelenchoides sp. 1 



(Fig. 29) 



Material examined. River Oich: 0.31 m; core 31, 19. River 

 Foyers: 0.22 m; core 40, 1 9. 



Horizon. Core 40, (1-2 cm); Core 3 1 , (2-3 cm). 



FEMALES, (n = 2). L = 387. 492 pm; a = 35, 33.4; b = 6.7, 8.2; c = 

 12.2, 13.9; c' = 4.5, 4.0; V = 67.7, 69; tail = 31.5, 35.4 pm. 



Head region smooth, slightly offset. Cuticle with fine striations 

 about 0.9 pm wide. Lateral fields with four lateral lines, inner pair 

 faint. Spear 10.2, 10.8 pm long with small basal thickenings. 

 Procorpus of oesophagus narrow; median bulb ovoid, valve well 



developed, located posterior to middle of bulb. Excretory pore less 

 than one body width posterior to median bulb. Vagina slightly 

 inclined anteriorly. Ovary outstretched anteriorly 116, 152 pm long. 

 Spermatheca not seen. Postvulval uterine sac apparently absent. 

 Anus distinct, anterior lip slightly raised. Tail conical, terminating in 

 a pointed ventral mucro. 



Remarks. Using Sanwal (1960) these females key out as A. 

 goeldi Steiner, 1941 primarily because the postvulval uterine sac is 

 absent. However, these females clearly differ from A. goeldi in both 

 head and tail shape. 



Aphelenchoides sp. 2 



(Fig. 30) 



Material examined. River Oich: 0.31 m; core 31, 19. 



Horizon. Core 31,(1-2 cm). 



FEMALE, (n = 1 ). L = 470 pm; a = 33; b = 8. 1 ; c = 16.2; c' = 3.5: 

 V = 72: tail = 29 pm. 



Head region smooth, offset by constriction. Cuticle with fine 

 annules about 0.9 pm wide. Lateral fields with four lines, inners very 

 faint. Spear 1 0.2 pm long with small basal thickenings. Procorpus of 

 oesophagus moderately wide; median bulb ovoid, valve well devel- 

 oped, located slightly posterior to middle of bulb. Excretory pore 

 opening slightly anterior to base of median bulb. Vagina slightly 

 tilted anteriorly. Anterior genital branch outstretched 204 pm long; 

 spermatheca 177 pm long with disc-like sperms. Postvulval uterine 

 sac 43.5 pm long without sperm. Anus moderately distinct. 



REMARKS. Additional specimens are needed in order to identify 

 this nematode with confidence. Morphometric measurements and 

 the anterior position of the excretory pore suggests that it may be 



Fig. 29 Aphelenchoides sp. 1. A-E. female. A. anterior region; B. tail; C. 

 habitus; D, vulval region; E, lateral field. Scale bars a = 10 pm, b = 50 

 pm. 



Fig. 30 Aphelenchoides sp. 2. A-E, female. A, anterior region; B, tail; C. 

 vulval region; D, habitus; E, lateral field. Scale bars a = 10 pm, b = 50 

 pm. 



