16 



C.J. FERRARIS. JR. 



mm). Rangoon Market, A. Herre, 14 Nov 1940, SU 39869 (2:172- 

 184 mm). 



HISTORY OF THE IDENTIFICATION OF THE 

 AYEYARWADDY RITA 



Day ( 1 873) provided the first mention of Rita from theAyeyarwaddy 

 River in his account of the fishes of India and British Burma, under 

 the nameSito ritoides (Valenciennes, 1 840), a name now considered 

 a junior synonym of Rita rita (Hamilton, 1822) (Jayaram, 1966). 

 Several years later Day ( 1 877) included the Ay eyarwaddy within the 

 range of Rita buchanani Bleeker 1853, another junior synonym of 

 Rita rita. Day acknowledged that Rita ritoides might have been the 

 appropriate name for the species, but departed from his earlier use of 

 that name and, without explanation, used R. buchanani instead. 



The name Rita sacerdotum was proposed in Anderson (1878 

 [1879]) for a species from the middle reaches of the Ayeyarwaddy 

 River. As noted by Jayaram (1966), several authors have attributed 

 the description of this species to Francis Day, presumably on the 

 basis of a statement in the book's acknowledgements (Anderson, 

 1878 [1879]: xxiv) which states that Day 'favored me with a list of 

 fishes collected on the First Expedition, and undertook the descrip- 

 tion of certain species'. However, the species described by Day are 

 those published elsewhere (Day 1870a, 1870b, 1871) and not the 

 ones that first appeared in Anderson (1878 [1879]). The style of 

 writing and the choice of anatomical characters are significantly 

 different from that of Day's other published species descriptions. It 

 is important to note that the actual publication date for the species 

 description, and for the volume as a whole, differs from that on the 

 title page. A statement in the published corrigenda that follows the 

 title page clearly indicates that publication was unexpectedly de- 

 layed past 1878, the date on the title page, and was issued, instead, 

 in 1879. 



Anderson's (1878 [1879]) description of Rita sacerdotum was 

 based on his field observations of living examples of the species that 

 were treated as pets by the residents of a Buddist temple as well as 

 a single specimen that was secured and illustrated. The account was 

 published in a summary of an expedition to western Yunnan, along 

 with accounts of other species from Yunnan and 'upper Burmah'. 

 Because of the title of the publication, some accounts have mistak- 

 enly cited the type locality of this species as Yunnan. 



In neither Day's ( 1 888) Supplement to the fishes of India, nor his 

 modified and updated version of his earlier book (Day, 1889) is 

 Anderson's Rita sacerdotum (or the other two fish species described 

 by Anderson) mentioned. The reason for this curious omission is 

 unknown. It is possible, but highly unlikely, that Day was unaware of 

 Anderson's book with its included species accounts. Day and 

 Anderson must have known each other, as evidenced by the above 

 mentioned acknowledgement of Day's assistance by Anderson. Day 

 may have considered the species to lie outside the scope of his own 

 book, as it was described from Upper, rather than British, Burma. 

 For whatever reason, Day's failure to include mention of Rita 

 sacerdotum in either of the two accounts he published on fishes of 

 southern Asia appears to have been a major factor in the subsequent 

 oversight of Anderson's name. 



Vinciguerra (1890) reported on a specimen of Rita from the 

 vicinity of Yangon, under the name Rita ritoides. He noted that his 

 specimen differed from the typical form of R. ritoides in the relative 

 length of the dorsal spine and the shape of the humeral process. 

 Vinciguerra compared his specimen with the description of Rita 

 sacerdotum, and decided that it too differed from his specimen on 



several features, but that the two specimens shared a comparatively 

 short dorsal-fin spine. On that basis, he concluded that two distinct 

 forms of Rita ritoides existed, one in Myanmar and one in India. 



After a period of more than a half century without any mention of 

 Rita from the Ayeyarwaddy, Jayaram (1966) revised the genus Rita 

 and concluded that two species were found in Myanmar: Rita rita 

 and R. kuturnee (Sykes, 1839). Inclusion by Jayaram of Rita rita in 

 the fauna of Myanmar appears to be based solely on the literature 

 accounts of Day ( 1 873) and Vinciguerra ( 1 890). Jayaram tentatively 

 placed/?z'fa sacerdotum into the synonymy of that species. All of the 

 specimens from the Ayeyarwaddy River, or elsewhere in Myanmar, 

 that were cited as having been examined by Jayaram were listed in 

 the account of Rita kuturnee. However, Rita kuturnee, and its widely 

 used junior synonym Rita hastata (Valenciennes, 1840), is a species 

 otherwise known only from the rivers of peninsular India. Talwar & 

 Jhingran ( 1 99 1 ) doubted that R. kuturnee actually occurs in Myanmar, 

 even though Jayaram (1977, 1981) had continued to list it in 

 subsequent accounts of the distribution of that species. 



Misra (1976) included Myanmar in the distribution of Rita rita, 

 but not that of/?, kuturnee. In his abbreviated synonymy for R. rita, 

 there is no mention of/?, sacerdotum, and the publication of Anderson 

 ( 1 878 [ 1 879]) is likewise missing from the literature cited. Talwar & 

 Jhingran (1991) similarly listed Rita rita as the only species of Rita 

 from Myanmar, but they tentatively included Rita sacerdotum in the 

 synonymy of that species. 



IDENTITY OF THE AYEYARWADDY SPECIES 

 OF RITA 



Although much of the recent literature suggests that the Rita species 

 inhabiting the Ayeyarwaddy River is Rita rita, the species in that 

 basin is, in fact, clearly distinct from R. rita. During this study, 

 specimens ofR. rita, from various parts of the Ganges basin, the type 

 locality of the species, were found to exhibit characters lacking in 

 specimens from theAyeyarwaddy. As first noted in Jayaram (1966), 

 the palatal teeth of theAyeyarwaddy Rita specimens are not arranged 

 in the broad, elliptical patches characteristic of/?, rita but, instead, in 

 'pear-shaped' patches that tapered posteriorly nearly to a point 

 (Figure la). In addition, the dorsal-fin spine of /?. rita is long and 

 stout with its length at least equal to the head length. The adpressed 

 spine usually extends well past the adipose-fin origin, at least in 

 large individuals. Day ( 1 877) noted that the relative size of the spine 

 was apparently allometric, and that in small individuals it may only 

 equal the head length, but that in larger individuals it may exceed 1 .3 

 times HL. In Ayeyarwaddy specimens, in contrast, the dorsal-fin 

 spine is never as long as the head and, more typically, it is shorter 

 than the head minus the snout, even in the largest specimens. 



In contrast to the prevailing view, Jayaram ( 1 966) identified the 

 Ayeyarwaddy specimens as R. kuturnee. It appears that his conclu- 

 sion is based primarily, but erroneously, on the similarity of the 

 palatal tooth patches in the two species. In placing theAyeyarwaddy 

 Rita into /?. kuturnee, he also looked beyond several striking differ- 

 ences between the two species. For example, the eye size of /?. 

 kuturnee is significantly larger than that of theAyeyarwaddy Rita. In 

 his diagnosis of /?. kuturnee, Jayaram (1966) lists the eye size as 

 'Eye 3.07 (2.70 to 4.70 of up to 8.80 in specimens from Burma) in 

 head length; 1.35 (1.00 to 1.50 or 3.90) in interorbital space width; 

 1.39 (1.00 to 1.50 or 3.00) in snout length.' It is possible that Jay- 

 aram interpreted the consistant disparity in eye proportions between 

 the Indian and Ayeyarwaddy specimens as a result of allometric 

 growth in /?. kuturnee. All of the specimens he examined from 



