Astiotrema turneri, Bray, Rodney A., Oosterhout, Cock Van, Blais, Jonatan & Cable, Joanne, 2006

Bray, Rodney A., Oosterhout, Cock Van, Blais, Jonatan & Cable, Joanne, 2006, Astiotrema turneri n. sp. (Digenea: Plagiorchiidae) from cichlid fishes (Cichlidae: Perciformes) of Lake Malawi, south­eastern Africa, Zootaxa 1319, pp. 43-58 : 45-46

Astiotrema turneri n. sp.

( Figs 1–3 )

Type­host: Pseudotropheus [= Metriaclima , Maylandia ] zebra (Boulenger 1899) , Perciformes , Cichlidae , zebra mbuna.

Other hosts: Pseudotropheus emmiltos (Stauffer et al. 1997) , Perciformes , Cichlidae ; Labeotropheus trewavasae (Fryer 1956) Perciformes , Cichlidae , scrapermouth mbuna; Melanochromis vermivorus Trewavas, 1935 , Perciformes , Cichlidae , purple mbuna.

Site: Intestine.

Type­locality: Thumbi West Island (14°01'22.83"S 34°49'16.63"E), Monkey Bay, Southern Malawi (03/09/05).

Other localities: Domwe Island (13°58'05.43"S 34°49'04.01"E) (06/09/05; 16/09/05) and Zimbawe Rock (13°57'40.73"S 34°48'08.88"E) (10/09/05), Monkey Bay, southern Lake Malawi; Mpanga Rocks (10°25'49.65"S 34°16'44.64"E) (19/09/05), Luwino Reef (10°26'17.41"S 34°17'00.16"E) (19/9/05) and Chirwa Island (10°27'48.94"S 34°16'35.77"E) (19/9/05), Chilumba, northern Lake Malawi; all Malawi.

Prevalence: P. zebra at Thumbi West – 3/24 (12.5%), at Zimbawee Rock 1/27 (3.7%), at Domwe Island – 1/61 (1.6%), at Mpanga Rocks – 2/16 (12.5%), at Luwino Reef 0/17 (0%), at Chirwa 0/12 (0%); L. trewavasae at Domwe Island – 1/6 (16.7%); M. vermivorus at Thumbi West – 1/6 (16.7%), at Domwe Island – 1/42 (2.4%); P. emmiltos at Mpanga Rocks – 3/18 (16.6%), at Luwino Reef – 5/17 (29.4%).

Intensity: 1–2.

Deposition of specimens: holotype BMNH 2006.6.6.1, paratypes BMNH 2006.6.6.2–12. Coll: JC, CvO & JB.

Etymology: The species is named after Prof. George F. Turner, University of Hull, who has devoted much of his career to the study of adaptive radiation and explosive speciation in Lake Malawi cichlids, and who introduced us to the field sites used in the current study.

Description: Based on 11 ovigerous specimens, some flattened at fixation. Measurements and ratios in Table 1 . Body oval, tapering at both ends, widest in midhindbody, bright orange in life ( Figs 1, 2 ). Tegument spinous to posterior extremity, spines sparser in hindbody. Oral sucker subglobular, subterminal. Prepharynx short or apparently absent, often restricted to posterior cavity of oral sucker. Pharynx oval. Oesophagus long narrow, rectilinear. Intestinal bifurcation in posterior forebody. Caeca fairly long, reaching to varying level of post­testicular region. Testes two, oval to indented, oblique to virtually symmetrical, separated by uterus, in anterior half of hindbody. Post­testicular distance generally long. Cirrus­sac elongate claviform, not reaching into hindbody. Seminal vesicle unipartite, narrower distally with surrounding gland­cells. Pars prostatica thick­walled vesicular proximally, narrower distally, surrounded by gland­cells, merges into short, indistinct ejaculatory duct ( Fig. 3 ). Genital atrium small. Genital pore median or slightly submedian, immediately anterior to ventral sucker. Ovary rounded, entire or indented. Mehlis’ gland postero­median to ovary. Canalicular seminal receptacle large, distinct, posterior to ovary. Laurer’s canal opens dorsally at level of Mehlis’ gland. Uterus fills most of body posterior to ovary, reaching extracaecally in fully gravid specimens, passes between testes, between anterior testis and ovary, and to genital atrium. Eggs numerous, tanned, relatively elongate. Metraterm of similar length to cirrus­sac with a narrow sheath of gland­cells. Vitellarium follicular, in lateral fields from level of oesophagus, pharynx, intestinal bifurcation or occasionally posterior part of ventral sucker, to posterior testis or just into post­testicular region. Excretory system not detected. Pore terminal.

Figures

FIGURES 1 – 3. Astiotrema turneri n. sp. 1. 1. Ventral view of holotype specimen from Pseudotropheus zebra, uterus in bold outline. 2. Ventral view of flattened specimen from Labeotropheus trewavasae, uterus in bold outline. 3. Terminal genitalia of specimen from P. z e b r a. Scale bars 1, 2 = 500 μm, 3 = 100 μm.