Rhinella marina
Creators: name: Valencia-Zuleta, Alejandro
name: Milto, Konstantin D.
name: Maciel, Natan M.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Amphibia
Anura
Bufonidae
Rhinella
Rhinella marina

description: Rhinella marina
is a large toad identified mainly by all cranial crests well developed; head wider than long; snout rounded in dorsal view; parotoid glands longer than wide, with triangular to ovoid shape, with indistinct borders; and dorsal skin covered by irregularly scattered warts (Easteal 1986; Kwet et al. 2006; Rodriguez & Duellman 1994). Etymologically the specific name marina is the Latin word for “of the sea”. Linnaeus described R. marina based on the description provided by Seba (1734). Seba, or someone who collected the toad, mistakenly believe that the species could be found on land and sea: “terra marique vivere patet” which means “is free to live on land and in the sea” (Easteal 1986).
When compared, the illustration (Fig. 1) and description of Rana marina (Seba, 1734) and the specimen ZISP 256 (Fig. 3) have many similarities. ZISP 256, as indicated in the first line of the tabula septuagesima et sexta: “ Num. I. Rana, Marina, Americana, rara; mas. ” (Seba, 1734), corresponds to a male. We confirmed this designation based on external characteristics outlined by Lee (2001) and Kelehear & Shine (2019), without resorting to incisions or forced mouth opening, to examine gonads or vocal slits respectively, given the age and relevance of this specimen. Firstly, we evaluated the robustness of the forearms (Fig. 4), assessing this condition by calculating the ratio of forearm width (at the midpoint of its length) to forearm length (FAR) of ZISP 256. We then compared this ratio with that of a female specimen (RMNH41769) of similar size (SVL of 129.78 mm) from Paramaribo, Suriname, the suggested most likely locality of the holotype (see discussion below), housed at the Nationaal Natuurhistorisch Museum, Leiden, The Netherlands. Our findings indicated that forearm width in ZISP 256 (19.6 mm) accounted for 57% of the FAR, while in the female was 34% (forearm width = 11.32 mm; FAR = 33.16 mm), supporting the more robust condition of ZISP 256. Secondly, there is a noticeable progressive shift in color from dark brown in the throat to light brown in the venter (Fig. 3C). It appears that the originally black throat turned brown due to preservation conditions. Thirdly, a dorsal colouration leaning more towards yellow than brown, commonly found in females (Fig. 3A). And finally, presence of nuptial pads, identified in ZISP 256 by a different color found on the thumb and adjacent fingers (Fig. 4A).
Also, as described and shown in the illustration by Seba (1734), ZISP 256 presents large and small tubercles along the body (dorsally), except on the head. In both, illustration and ZISP 256, the head shape is rounded in dorsal view (Fig. 3D); cranial crests are present and well developed (Fig. 3D–E); parotoid glands have ovoid shape (Fig. 3E); with dark patches arranged in the form of broad, interrupted dorsolateral stripes, parallel, well-marked, with the presence of tubercles of different sizes that arise in the anterior region of the parotoid glands and end on each side of the cloaca, which appears to be an effect of the status of preservation of ZISP 256 (Fig. 3A); and interdigital webbing present on hindlimbs (Fig. 3G).
However, different from the illustration, ZISP 256 is fixed and conserved with arms and legs folded (Fig. 3C). In the description of Seba (1734) (tabula septuagesima et sexta): “ Ubi pedes ejus antici, & postici, extensi lunt, longitudine dimidium cubitum excedit; neque tamen extendi satis nune potest, quia exsiccata est...” in literal translation means: “When its forelegs and hindlegs are stretched out, they exceed half an ell in length; fact is it cannot be extended, because it is dried out”. It appears that the description and illustration was done before the specimens was dried out. Most likely the specimen was described still fresh and perhaps where it was collected as might be suggested by the text: “ Oculi grandes, lucidi” which means: “Eyes large, bright”.
Also, the size ratio of hands and feet differs between ZISP 256 and the illustration. To facilitate comparison, we show ratios of hand length (HAL) to forearm length (FAR) and foot length (FL) to tibia length (TIL) from ZISP 256 and the illustration. The measurements of ZISP 256 are provided below with their redescription, while those for the illustration were estimated, in pixels, with the help of the ImageJ software v1.5. (Schneider et al. 2012) based on an illustration from black-and-white copy of Seba (1734) available at <https://www.biodiversitylibrary.org/>. ZISP 256 (HAL/FAR = 0.96) has hands slightly larger than the illustration (HAL/FAR = 0.90) and feet (FL/TIL = 0.94) 30% larger than the illustration (FL/TIL = 0.57). The limb digits also differ in their relative length of the fingers I <II <IV <III in the illustration (Fig. 2) and II <IV <I <III in ZISP 256 (Fig. 3F–G) and toes I <V <II/IV <III in the illustration (Fig. 2) and I <II <V <III <IV in ZISP 256 (Fig. 3F–G). Furthermore, the termination of the digits also differs. In the illustration (Fig. 2), digits are rounded and widened, resembling adhesive disc, whereas in ZISP 256 (Fig. 3F–G), digits are rounded but not widened. These differences may stem from the illustrator’s interpretation, potentially influenced by folded arms and legs condition observed in ZISP 256.
Comparisons and diagnoses recovered from illustrations found in Seba’s book can be a challenging task (e.g., Lavilla et al. 2013). Initially books were sold black-and-white, and thus, the quality of the representation of the drawings prevents an unambiguous comparison to the high-resolution photos we presented here. It is known that copies of Seba’s books were colored individually by many illustrators, perhaps at the own expense of the buyers (Müsch 2001). Thus, different quality of drawings and paintings can be found among books printed (see Fig. 1). Maybe the illustrators adapted the colors by comparing to other known species, but not necessarily the actual colors, since it is most likely they did not access the specimens (Bauer 2012; Müsch 2001). Perhaps birds and mammals attracted more the attention of illustrators, since the drawings found in Seba’s books of these species seem to be more faithful to reality. Although we suggest that the comparison of coloration between photos and illustrations should be done with care, it appears that it is somehow close to the drawing we represent here. We only note that there is a slight difference in coloration between ZISP 256 and the illustration, as the beige patterns in some regions of the body (e.g., irregular beige mid-dorsal area, legs and, glands) could indicate a rupture of the integument due to preservation or friction with the glass jar.
Please see detailed description below of the holotype following Pramuk’s (2006) nomenclature for cranial crests and Heyer et al. (1990) for snout shapes. Measurements were taken using a digital caliper (to nearest 0.1 mm) and follow Maciel et al. (2007) and Narvaes & Rodrigues (2009): snout-vent length (SVL); head width (HW); head length (HL); head height (HH); maximum length of parotoid gland (PGL); maximum width of parotoid gland (PGW); tympanum diameter (TD); eye diameter (ED); eyelid width, perpendicular distance from the inner edge to the outer edge of the eyelid (EW); interorbital distance (IOD); eye to nostril distance, between anterior corner orbit and posterior margin of the narial opening (END); internostril distance (IND); snout to nostril distance (SND); upper arm length (UAR); forearm length (FAR); hand length (HAL); thigh length (THL); tibia length (TIL); tarsus length (TL); foot length (FL). The webbing formulae follows Savage & Heyer (1997).
Description of the holotype ZISP 256: Adult male (SVL= 141.9 mm; Fig. 2), in good condition of preservation. General body aspect robust (Fig. 3A). Head slightly wider than long (HL/HW=0.75); SVL 2.66 times longer than HW; snout rounded in dorsal view (Fig. 3D) and vertical in lateral view (Fig. 3E); roof of the skull slightly concave (Fig. 3D); cranial crests present, developed and thickened (Fig. 3D); canthal crests short, not in contact at the tip (Fig. 3D); preorbital crests in contact with the eye, as well as with canthal and supraorbital crest (Fig. 3E); supraorbital crests slightly straight, connecting with parietal and postorbital crests (Fig. 3D); postorbital crests short, perpendicularly to parietal and supraorbital crests (Fig. 3D); pretympanic crests short, reaching the medial portion of the eye and in contact with the eye itself (Fig. 3D); supratympanic crests short, partially concealed in the posterior region by the parotoid glands (Fig 3D–E); parietal crests thin, almost indistinct, perpendicular to postorbital and suborbital crests (Fig 3D); suborbital crests forming an slightly arc-shaped curve, touching the lips (Fig. 3E); canthus rostralis straight (Fig. 3D–E); loreal region slight concave, smooth (Fig. 3D–E); nostrils large, oval and laterally directed (Fig. 3D); IOD twice wider than ED (IOD/ ED=1.87); eyelid slightly smaller than ED (EW/ED=0.84), granular, protruding and thickened laterally above the eye (Fig. 3D); ED twice times longer than TD (TD/ED=0.49); tympanic membrane ovoid, partially concealed by the parotoid gland (Fig. 3E); tympanic annulus indistinct (Fig. 3E); dorsum of the head smooth (Fig. 3D). Parotoid glands longer than wide, ovoid with indistinct borders (Fig. 2A–B); PGL twice times longer than PGW (PGL/PGW =2.01). Relative fingers length II <IV <I <III; fingers with slight lateral fringes and tips keratinized, but without basal webbing (Fig. 3F); subarticular tubercles low, with irregular shape (Fig. 3F); supernumerary tubercles rounded, low, distributed irregularly in the palm (Fig. 3F); outer palmar tubercle large and rounded, twice times larger than inner palmar tubercle (Fig. 3F); inner palmar tubercle ovoid at base of finger I (Fig. 3F); finger I, more thickened than the others (Fig. 3F); nuptial pads slight visible on the dorsolateral surface of fingers I, II and III (Fig. 4A); forearm and arm robust (Fig. 3C,F). Relative toes length: I <II <V <III <IV (Fig. 3G); toes with lateral fringes, tips keratinized, and basal digital webbing (Fig. 3G); digital webbing formulae: I 1–2 + II 1 + –3 III 2 + – 31/2 IV 31/2 –2 + V (Fig. 3G); subarticular tubercles low, oval (Fig. 3G); supernumerary tubercles small, linearly distributed in the plantar surface (Fig. 3G); outer and inner metatarsal tubercle ovals, protruding distally, with both being equal in size (Fig. 3G); tarsal fold present (Fig. 3G); TIL approximately 2.56 times smaller than the SVL (TIL/SVL=0.39). Dorsal skin granular (Fig. 3A); covered by large, rounded, and oval tubercles of different sizes (Fig. 3A–B); tubercles of similar sizes, smaller and densely in the limbs (Fig. 3B). Venter wrinkled to areolate with tubercles with keratinized tip (Fig. 3C).
Coloration in preservative of ZISP 256: Heterogeneous brown dorsal coloration with a large and irregular mid-dorsal beige (dark yellow) area with keratinized tubercles rougher on both sides (Fig. 3C). Nuptial pads dark brown. Venter beige with irregular brown spots at the center; throat slight brown (Fig. 3C); hind limbs with several, irregular, brown reticulations (Fig. 3C).
Measurements of the holotype (in mm): SVL 141.9; HL 40.3; HH 28.5; HW 53.3; PGL 55.3; PGW 27.5; TD 5.9; ED = 12.1; TD = 5.9; EW = 10.2; IOD = 22.7; END = 10.5; IND= 9.8; SND = 4.9; UAR= 38.1; FAR = 34.1; HAL = 32.7; THL = 62.1; TIL = 55.6; TL = 30.3; FL = 52.2.
The type locality of Seba’s specimens also has been subject of historical discussion (see the case of Rana margaritifera Laurenti, 1768 in Lavilla et al. 2013). The type locality of R. marina was originally indicated as originating from America (Linnaeus 1758; Seba 1734), but it was restricted to Suriname by Müller & Hellmich (1936) and Schmidt (1941), as apparently this is the most probable area of for many specimens of Seba’s collections. Based on information indicated by Seba (1734), we suggested the coastal area in Suriname, in particular, Paramaribo as the type locality of the species. Seba visited incoming ships in Amsterdam and bought specimens from many parts of the world (Boeseman 1970). As in the early 18 th century only the area around Paramaribo, Suriname, was settled, it is most likely that Seba’s specimen came from there (Hoogmoed 1973). Duellman & Wiens (1993) designated the neotype of Scinax ruber (Laurenti, 1768) based on the same assumption. Also, as stated by Easteal (1986), the specific name marina was mistakenly used to indicated that the species could live on land and sea. Thus, it is not unlikely that we could assume that the type could have been collected in an area close to the coast. Also being an old town and a departure point (i.e., port), removal of specimens for trade was easier. However, this is only a suggestion and more detailed information should be evaluated in future studies, perhaps by inspecting documents of diaries, trades, and ship routes of that date.
The finding reported herein significantly contributes to nomenclature of the species Rhinella marina as well as the group and clade it was nested and also named (Pereyra et al. 2021). Although there are still many unresolved gaps regarding the diversity and history of names related to the R. marina group, such as proper diagnoses for many species of the group [see Acevedo et al. (2016) and Pereyra et al. (2021)], found type specimens (e.g., Bufo diptychus Cope, 1862: Lavilla & Brusquetti 2018), and description of candidate species (Pereyra et al. 2021), we consider that the redescription of the holotype of the oldest species of the group can clarify and improve its understanding.
description: Published as part of Valencia-Zuleta, Alejandro, Milto, Konstantin D. & Maciel, Natan M., 2024, Redescription of the holotype of the cane toad Rana marina Linnaeus, 1758 (Anura: Bufonidae), pp. 135-143 in Zootaxa 5453 (1) on pages 138-141, DOI: 10.11646/zootaxa.5453.1.10, http://zenodo.org/record/11232977