A historical specimen of the Fishing Cat, Prionailurus viverrinus (Bennett, 1833) (Carnivora, Felidae) from Singapore in the zoological collection of the Naturalis Biodiversity Center, Leiden

The Fishing Cat is not a species known to inhabit Singapore. However, a historical specimen stated to have come from Singapore in 1819 and attributed to Pierre-Médard Diard (RMNH.MAM.59688) is now housed at Naturalis Biodiversity Center, Leiden, the Netherlands. Two hundred years after it was obtained, the mounted skin and skull of this specimen, including specimen labels, were photographed and digitally catalogued. Four sets of annotations from labels and a document detailing records and a receipt of specimens sent by Diard to Leiden are presented to ascertain the specimen’s identity, followed by a historical account of Diard based on a reconstruction of the timeline of key events of Singapore’s natural history. Subsequently, the specimen is examined to confirm its taxonomic identity using comparative morphometrics with other museum specimens, and data associated with the specimen are ana-lysed to determine the origins of this specimen. We conclude that the current evidence does not allow confirmation of the specimen’s status as having been collected in Singapore or being obtained from the pet trade. If the specimen was an imported specimen, it would point towards a trade in rare and large animals in Singapore and the region from as early as 1819. Presently, the specimen remains one of the few extant zoological specimens obtained in Singapore in 1819 and the only one currently known outside of England.


Introduction
The Fishing Cat, Prionailurus viverrinus (Bennett, 1833) is a medium-sized, nocturnal species of the family Felidae. Its natural distribution is still unclear but current known occurrence records suggest that this species is widely distributed in South and Southeast Asia from Pakistan in the west to Cambodia in the east, and from the Himalayan foothills in the north to Sri Lanka and peninsular Thailand in the south (Mukherjee et al. 2016). Based on museum records, the species has also been reported from the Malay Peninsula, Java and possibly Sumatra (e.g., Blanford 1888Blanford -1891Jentink 1892;Brongersma 1935). These records from the Malay Peninsula that were based solely on museum specimens have generally been assumed to have been the result of mislabelling, misidentification or material obtained from the pet trade (Duckworth et al. 2009).
The Fishing Cat is absent from present-day Singapore and the origins of a museum specimen from Singapore housed in the Naturalis Biodiversity Center of the Netherlands (RMNH) need careful investigation. The first mention of the Naturalis specimen was in Jentink (1887: 83), then again by Jentink (1892: 99) and subsequently by Brongersma (1935: 13). This record was mostly overlooked until van Bree and Khan (1992: 80), citing Brongersma (1935) wrote, "[i]n the National Natural History Museum at Leiden, the Netherlands, there is a Fishing Cat collected by P. Diard in Singapore in 1819". Over a decade later, Duckworth et al. (2009: 7) referred to this same specimen but in reference to Malacca "c.1820s [date inferred from the collector's identity: Diard], RMNH". The authors further stated that the specimen is "presumably the Malacca specimen(s) examined by Swinhoe (1862)" which suggests that they may not have known that there were labels associated with the Singapore specimen and were only aware of the collector, leading them to infer the date and locality. The origin of this Singapore specimen of the Fishing Cat in the RMNH therefore, has not been resolved.
As a follow-up study on the historical account of two French naturalists Diard and Duvaucel who collected with Raffles (see below), researchers from Singapore's Lee Kong Chian Natural History Museum (LKCNHM), and the Netherlands' Naturalis Biodiversity Center, Leiden (RMNH) searched through zoological collections in RMNH in November-December 2019 to locate and catalogue, amongst others, the Fishing Cat specimen. This work aims to confirm the taxonomic identity of the Fishing Cat specimen and reconstruct the history of this specimen based on a timeline of key events in the early natural history of Singapore to provide a better understanding of the original fauna of Singapore.
The first Singapore Expedition (May-June 1819) Two French naturalists, Pierre-Médard Diard (1795-1863 and Alfred Duvaucel (1793-1824), who were employed by Sir Thomas Stamford Bingley Raffles (1781Raffles ( -1826, were among the earliest collectors of zoological material from Singapore and first visited Singapore in early 1819 with much of their collecting taking place between 31 May to 28 June 1819 (Pilon and Weiler 2011;Low 2019;Weiler 2019;Low 2021 in press;Low et al. 2021).
During the four-week period in May and June 1819, which may be referred to as the first Singapore expedition, Diard and Duvaucel appear to have collected the majority of zoological specimens (Low 2021 in press;Low et al. 2021). The expedition resulted in many firsts from Singapore (in the scientific sense): the collection of the first mammal to be recorded, the Dugong (Dugong dugon (Müller, 1776)), the earliest natural history illustration (of a Spiny Turtle (Heosemys spinosa (Gray, 1831)), the first mammal to be named, the Cream-coloured Giant Squirrel (Ratufa affinis (Raffles, 1821)), the first primate to be described, the Banded Leaf Monkey (Presbytis femoralis (Martin, 1838)), and the first bird to be named, the Green Broadbill (Calyptomena viridis Raffles in Horsfield, 1822) (Low 2019;2021, in press;Low et al. 2021).
Only two specimens from this 1819 collection are currently known to be extant: the Banded Leaf Monkey, Presbytis femoralis (Martin, 1838), and the Green Broadbill, Calyptomena viridis Raffles in Horsfield, 1822(Napier 1985Wells and Dickinson 2010;Wells 2013;Low and Lim 2015). It is also known that material collected from Singapore in 1819 also resides in other collections (Noltie 2009) and recent research has shown that Raffles gave 21 bird specimens from Sumatra to Lord Edward Smith Stanley (Wilson 2021). There is therefore the possibility that further research may uncover material collected from Singapore in 1819 in other collections in England or elsewhere.
In March 1820, the two French naturalists parted ways with Raffles after a falling out and the vast majority of their collections were seized by Raffles; the French naturalists retained specimens for which there were triplicates (Raffles 1821: 239, 240;Raffles 1830: 713;Burkill 1916;Bastin 2019: 288;Weiler 2019;Low 2021 in press). The duplicates were sent on the Mary and used by Raffles in his Descriptive Catalogue (Raffles 1821;Raffles 1822) and in Horsfield's Zoological Researches in Java (Horsfield 1821-1824). The primary set of material was retained with Raffles in Bencoolen (Bengkulu) but was lost when the Fame burned and sank in 1824 (Noltie 2009: 9-13;Wilson 2021: 40, 41).
Raffles explicitly stated in his Descriptive Catalogue (Raffles 1821: 249), that only two species of the genus Felis were in his collection (which included material from the first Singapore expedition): "the Royal Tiger, and a species of Tiger-cat" identifying the latter as Felis bengalensis (now under Prionailurus). Following the death of Raffles in 1826, his wife, Lady Sofia Raffles, published his memoirs with an appendix entitled Catalogue of Zoological Specimens by Vigors and Horsfield (Raffles 1830: 633-697) detailing the material collected in the two months following the loss of the Fame (Noltie 2009: 9-13;Wilson 2021: 40). No species of cat from Singapore is listed in this appendix or in the Zoological Researches of Java (Horsfield 1821(Horsfield -1824Raffles 1830: 636-637).
Over four decades later, Leo Daniel Brongersma (1907-1994, a Dutch zoologist and, from 1958, director of RMNH, re-examined the fossil and recent felid material from the Malay Archipelago in RMNH (Brongersma 1935). He referred F. viverrina to its currently accepted generic combination of Prionailurus viverrinus (Bennett, 1833) and gave the following remarks: "1 ex., 'Singapore', leg. Diard, cat. syst.: b, mounted, cat. ost.: b, skull" (i.e., specimen b of Jentink's catalogue, i.e., Jentink 1887) (Brongersma 1935: p. 13). Brongersma (1935: 13) further stated that "[o]ur Museum possesses a specimen labelled 'Singapore', but as the species has not been recorded from that island in recent times (it is not mentioned by Chasen (1924Chasen ( , 1925 this locality-record seems extremely doubtful to me". Brongersma (1935: 13) was referring to Chasen's preliminary account of mammals in Singapore that were published in two parts. In his conclusion, Chasen (1925: 87-88) made several remarks on species for which he considered "very doubtful records" which was followed by a list of species for which confirmation of local status was needed (while also taking the possibility of some species being imported into Singapore into account), and finally he provided a list of species of what he called "the true Singapore land fauna". The Fishing Cat (either as Felis or Prionailurus viverrinus) was not listed or discussed by Chasen (1924;1925).

RMNH.MAM.59688 is the specimen b of Jentink and Brongersma
The following four sets of annotations accompany the specimen. The annotations are based on three labels found in the box labelled "cat. ost. b" (i.e., specimen b of the "Catalogue ostéologique des Mammifères", i.e., Jentink 1887; Fig. 1D) with a skull specimen in it and one label pasted on the pedestal of the mounted skin ( Fig 1. Handwritten label pasted on a piece of wood ( Fig. 2A). The French text is presumed to be in Diard's handwriting because it bears a close resemblance to a letter written by Diard while he was in Singapore (see Tham et al. 2019: 163). While most of the text is easy to read, there are some parts which have become illegible. Also, we suggest that due to variation of spellings, the specific name on the label (the first line) could be interpreted in three different ways. We suggest the following transcription: Interpretation 1:

Felis leucojalamus Diard
Interpretation 2: Felis leucojalamis/ Felis leucopalmis Diard   The phrases "Felis leucojalamus", "Diard", "1819" and "Singapore" appear in Jentink's and Brongersma catalogue. It is possible that Jentink may only have glanced at the label and thought that Diard had intended to propose a new name for a "espèce inédite" (translation: unpublished species) from Singapore. As seen from his catalogue entry, Jentink (1887) read "Felis leucojalamus", attributing the name to Diard (interpretation 1). However, after enhancing the image of the label to clarify the handwriting, it clearly shows that the last character of the epithet is an "i", thus it should read "leucojalamis" (interpretation 2). Nevertheless, the specific epithet "leucojalamus" is incomprehensible: "leuco" is derived from the Greek leukós, meaning "white, bright", the second part "jalamus" or "jalamis" is not found in either Latin or Greek. Furthermore, neither Jentink nor Brongersma mentioned the last line of the note (in translation): "it is also found in Cochinchina and Cambodia".
More details emerged from Natuurkundige Commissie Archives Online (NCO: https://dh.brill.com/nco) published by Gasso et al. (2020), which showcases specimens, drawings and illustrations as well as documents, such as field books, notes, shipping lists, and correspondence of members of Natuurkundige Commissie voor Nederlandsch-Indië. From NCO, we discovered a twopage document of shipment sent by Diard to Leiden in March 1830 (Fig. 3A, B). The document listed a specimen of "Felis leucopalmis du détroit de Singapour" (translated: "Felis leucopalmis from the Strait of Singapore"). We assumed that Schlegel interpreted the name based on Diard's label of the Singapore's specimen of Fishing Cat that was probably already hard to read at the time. In the same shipment as the Singapore's Fishing Cat were specimens from Borneo, Java, Cambodia, Malacca and Sumatra, including a nomen nudum Felis strepsilura from Java (now Prionailurus planiceps; interestingly another wild cat adapted to hunt aquatic prey, but not presently known from Java).
The third interpretation of the specific name is transcribed as "bengalensis" because Diard seemed consistent in writing certain characters such as "i" (with a striking dot) and "s" as in "is" which suggests that the second element after the word "Felis" should be read as "bengalensis" with a cursive "b" (Fig. 2A). Another possible explanation for "bengalensis" is perhaps the specimen was part of triplicates that were allowed to be retained by Diard and Duvacel following the separation with Raffles (as discussed above). Felis bengalensis in 1819 was still the only cat of similar description known in South and South-East Asia.
In addition, there is an inscription in (possibly) Jentink's handwriting written on the wood: "b Felis viverrina," 2. The second label is in possibly Jentink or Schlegel's handwriting showing catalogue number, species name, year, and locality (Fig. 2B). Note that locality name "Singapore" is spelt in English:  (Fig. 2D) could be one of the earliest preliminary identifications of this specimen, but the information is not captured in any of the catalogues. The label had the following information written in the style Temminck used, but it is not written by him (compared with the other three labels), with F. viverrina as a species name and a reference of author was attributed to "Hardw." (Hardwicke) followed by a publication name, "Ind : Zool:" (= "Illustrations of Indian Zoology", Gray 1832-1835), "Diard" as collector and "Singapoor": Felis viverrina, Hardw. Ind: Zool. voy: Diard. Singapoor.
In addition, the pedestal bears the following inscriptions: "849" (written in ink), "314", and "KOP" (written in pencil, means head or skull) (see Fig. 2D, arrowed), but we were not able to determine the meaning of these numbers or letters.
Although some of the material depicted in the "Illustrations" was stated to have come from Singapore (Low and Pocklington 2019: 156-159), the "Viverine Cat" is not one of them. The reference to Hardwicke on the label was probably an 'update' to the identity of the specimen when it was later found to be conspecific with the species figured in the "Illustrations".
But was the specimen RMNH.MAM.59688 that of a Fishing Cat or a misidentified closely related but smaller Leopard Cat, Prionailurus bengalensis (Kerr, 1792) that is native to Singapore and Malacca?

RMNH.MAM.59688 is a Fishing Cat
We examined specimens of six Fishing Cats and nine Leopard Cats from the Malay Peninsula from the RMNH and the Zoological Reference Collection of Lee Kong Chian Natural History Museum, National University of Singapore, ZRC; see Suppl. material 1) and compared them with RMNH.MAM.59688 (the Diard specimen). Although no measurements of the live animal are associated with specimen RMNH.MAM.59688 or its labels, the skin and skull provide characters to identify the cat in question (Fig. 1).
We took the following measurements using callipers: i) greatest length of skull from premaxilla to occipital (GL), ii) condylobasal length from back of occipital condyle to premaxilla (CBL), iii) condylocanine length from back of occipital condyle to front of the canine (CCL), iv) maxillary toothrow length (MT), v) zygomatic width (ZW), vi) height of canine from base to tip (C1H), vii) greatest length of bullae (BL), and viii) greatest width of bullae (BW). One missing data field owing to a broken zygoma was filled with the mean for the species. A principal component analysis (PCA) was performed for the eight cranial measurements transformed to a log scale (Meijaard et al. 2017;Jackson et al. 2021). Statistical analyses were conducted in RStudio 1.1.463 (RStudio, Inc.) using the prcomp operation.
The greatest length of the skull RMNH.MAM.59688.a at 13.4 cm is within the range of Fishing Cat skulls (Pocock 1939), and far exceeds the mean length of Leopard Cat skulls (9.01 cm; range: 8.19-9.55 cm; n = 9) from the Malay Peninsula. The Diard specimen is likely a young adult as the skull's basilar suture has not fused. The PCA revealed that the Diard specimen grouped with Fishing Cats, which were distinctly separated from Leopard Cats from the Malay Peninsula (Fig. 5). In addition, the specimen grouped more closely with Javan Fishing Cat specimens rather than those of Indochina along the PC2 axis. Components 1 and 2 account for 98.6% of the total variance explained (see Suppl. material 1). In addition, the dark spots on the RMNH.MAM.59688 specimen are large and solid (Fig. 1E), which differs from the "shaded" spots of Leopard Cats on mainland Southeast Asia, which are always lighter anteriorly and darker posteriorly (Groves 1997). Further, the proportion of its tail, which is less than half the head and body length is much shorter than that of the mainland Leopard Cat (Pocock 1939;Groves 1997). These characters help determine that the specimen is P. viverrinus and not a misidentified Leopard Cat.
With the species identity certain, and given that the place and date of acquisition coincide with Diard being in Singapore during his visits to Singapore in 1819 (as discussed above), how then did a specimen collected by Diard end up in RMNH?
The Singapore collections and Diard's collecting post-1819 To date, apart from the Fishing Cat specimen, all the zoological specimens collected in 1819 that are still extant are currently thought to be in the collections of what is presently known as the Natural History Museum in London (NHMUK) (as discussed above). This material could have entered the collections of the NHMUK from two possible sources. Some material was sent back to the Honourable East India Company's (HEIC) museum in London and was later transferred to the NHMUK after the HEIC museum disbanded in 1858 (Ratcliff 2016). The other possible route was via the material sent back by Raffles that formed the basis of the museum of the Zoological Society of London (Wheeler 1997).
It is also known that Diard and Duvaucel sent material to the Muséum national d'Histoire naturelle in Paris (MNHN) in 1820 (Weiler 2019). However, no material from Singapore dating from 1819 is known in the MNHN .
Following the separation with Raffles, Diard and Duvaucel also parted ways and Diard travelled to several places in Southeast Asia (including what is today Vietnam) for 26 years before returning to Europe in 1843, and then once again returning to Southeast Asia in 1848 (Weiler 2019). At this time, Diard was also employed as a member of "Natuurkundige Commissie voor Nederlandsch-Indië" (Committee for Natural History of the Netherlands Indies, hereafter the Committee) (Weber 2019). The Committee's specimens arrived in Europe in 1830 and at that time RMNH regularly exchanged items from Asia with other natural history museums in Europe (Weber 2019).
From the RMNH's public database, BioPortal (https:// bioportal.naturalis.nl, accessed on 13 September 2021) and accession records, over 800 specimens were collected or donated by Diard (while he was still alive and some posthumously) from various places ranging from as early as 1818 to as late as 1869, of which 20% are mammals. For the same period, the database contains 19 specimens (representing 13 species) from Singapore associated with Diard of which the 1819 Fishing Cat specimen appears to be the oldest. Other Diard specimens were acquired by the RMNH in 1858 (viz., eleven specimens of birds and a squirrel) either collected and/or donated by Diard himself for the Committee (Table 1). Three specimens of Presbytis femoralis (Martin, 1838) from Singapore (identified as Semnopithecus neglectus Schlegel, 1876) with Diard as collector were mentioned in Jentink's 1892 catalogue (Jentink 1892: 12-13). In the same catalogue, the two specimens of this species that Jentink referred to as specimens a and c, were dated in 1869 which suggests that they were donated posthumously while specimen b was accessioned in 1859 and could have been donated to RMNH by Diard (Table 1).
In around 1854, Diard was appointed as director of the botanical gardens at Buitenzorg (now Bogor) in the West Java province in which during his tenure, he continued collecting specimens at several places including Ceylon (now Sri Lanka) and sending his collections back to MNHN (Weiler 2019: 40). Diard died on 16 February 1863.

Conclusions
This study concludes that: (1) the Diard specimen is indeed a Fishing Cat, Prionailurus viverrinus (Bennett, 1833); (2) that the label was almost certainly written by Diard himself and that the Singapore locality was intended; (3) the 1819 date when it was obtained coincides with Diard's visits to Singapore. It is interesting to note that the handwritten label indicated that the Felis leucojalamus/leucopalmis/bengalensis can be found in two other places, Cochinchina (now the southern part of Vietnam) and Cambodia which were part of his later travel routes. Diard's trip to these two places commenced between 1821 and 1822 which means there was a gap of at least two years after the time spent in Singapore in 1819. The inclusion of Cochinchina and Cambodia on the label suggests that Diard wrote this label after he returned from those places but that the specimen had been obtained in Singapore in 1819. However, we are not able to conclusively determine if Diard collected the cat himself in Singapore or if he purchased a specimen that was transported to Singapore.
RMNH.MAM.59688 was accessioned at the RMNH in March 1830 as evidenced by a document signed by H. Schlegel (Fig. 3) which explains how this specimen Figure 5. The PCA revealed that the Diard specimen (RMNH.MAM.59688) grouped with Fishing Cats, which were distinctly separated from Leopard Cats from the Malay Peninsula. The specimen grouped more closely with Javan Fishing Cat specimens rather than those of Indochina along the PC2 axis.
of Fishing Cat was brought to Europe from Singapore. However, further analysis will be required to determine how the 1819 specimen evaded Raffles's seizure of Diard's collections given the value of this animal, although it could be postulated that Diard might have hidden it or that it was part of triplicates of the Singapore first expedition. A study of Diard's correspondence with his brother and relevant papers in the archives of the MNHN or RMNH may help to answer these questions, but this is beyond the scope of our study. It should be noted that if RMNH.MAM.59688 was an imported specimen that Diard acquired in Singapore, it would point towards a trade in rare and large animals in Singapore and the region from as early as 1819. The morphological similarity of RMNH. MAM.59688 to Javan Fishing Cat skulls lends support to the possible Javan origin of the specimen through trade.
An unlikely alternative scenario would be that the specimen was part of a native Singapore population and that the distribution of the Fishing Cat was or is a lot more widespread than hitherto known or accepted. To date, however, there have been no confirmed reports of Fishing Cats in the Malay Peninsula while the possibility of their occurrence in Sumatra is considered speculative in light of insufficient evidence (Duckworth et al. 2019).
This reconstruction of the history of Diard's Fishing Cat specimen from Singapore in RMNH suggests that there may be more Singapore material collected in 1819 yet to be discovered. This is the third species (other than the Green Broadbill and the Banded Leaf Monkey) for which the material collected during the first Singapore expedition is still extant.