Conolophus marthae, Gentile, Gabriele & Snell, Howard, 2009

Gentile, Gabriele & Snell, Howard, 2009, Conolophus marthae sp. nov. (Squamata, Iguanidae), a new species of land iguana from the Galápagos archipelago, Zootaxa 2201, pp. 1-10 : 2-8

Conolophus marthae new species

Galápagos pink land iguana Figs. 2–5

Holotype. A free-ranging adult male permanently branded with the number 117. A Passive Integrated Transponder (PIT) with the number 091-601-303 was hypodermically inserted in one of the posterior legs. The individual was captured and released approximately four km north of the Equator on the top of Volcan Wolf, Isla Isabela, Galápagos National Park, Ecuador (0.03792° N; 91.36324°W, datum WGS84, as recorded by a Garmin 12CX handheld GPS). The individual was captured by A. Jaramillo on June 8th 2006, blood was drawn by G. Gentile. Photos were shot by G. Gentile. Blood in lysis buffer voucher n. MCZRR 450 (as reported in the Genbank records FJ716129 and FJ716130 ) is hosted in the reptile collection (as specimen n. R450) of the Civic Museum of Zoology ( MCZR, Rome, Italy,). Original photo files, named as “Morphobank_m27772.jpg” ( Figure 2 ), “Morphobank_m27773.jpg, Morphobank_m27774.jpg, M o r p h o b a n k_m 2 7 7 7 5. j p g, M o r p h o b a n k _m2 7 7 7 6. j p g, M o r p h o b a n k _m2 7 7 7 7. j p g, a n d Morphobank_m27778.jpg” ( Figures 3 A, 3B, 3C, 3D, 3E, and 3F, respectively), and the movie “Morphobank_m27779.wmv” are included in a project titled as the present paper, hosted in Morphobank (http://www.morphobank.org). Such photos and video form a basis of the description and should be considered also as illustrating the type specimen, for purposes of Article 73.1.4 of the Code ( ICZN, 1999), but see also the paragraph “Notes added in proofs”. All material refers to the same individual (free ranging, with PIT number 091-601-303), elected as Holotype.

Diagnosis. Conolophus marthae sp. nov. is distinguished from C. pallidus and C. subcristatus by the following color pattern: pinkish head, pinkish and black (dark) body and legs, with a typical black-striped pattern on the mid to posterior dorsal body; stripes are along the dorsal-ventral axis, may be irregular and their number variable; stripes may join to form a more complex pattern; stripes occur on the ventral body, but are less evident; dark tail.

Other distinctive, but slightly variable morphological traits co-occur in males: i) adipose nuchal crest with small or reduced conic scales, ii) poorly elevated (pyramid-shaped) or almost flat dorsal head scales.

Conolophus marthae sp. nov. is also distinguished from the other two congeneric species by a distinctive pattern of head-bob behavior ( Fig. 6 , see Morphobank accession code: p241).

The new species is unequivocally distinguished from C. pallidus and C. subcristatus by the several diagnostic sites in the sequence of the control region and cytochrome b gene of the mtDNA, reported in Table 1, and by a completely different, non overlapping, size-range of alleles at the microsatellite locus CS7 ( Tzika et al., 2008; Gentile et al. 2009). Alleles at locus CS7 range between 245 and 333 bases (as defined in Gentile et al. 2009).

Description of Holotype in life.

Sex: Male

Age : Adult

Weight: 5.0 Kg.

Morphological measurements: SVL: 47.0 cm; VTL: 61.4 cm; head length: 78.22 mm; head width: 63.76 mm; internostril distance: 17.89 mm; eye-eye distance: 35.19 mm.

Control region

786 465 12 24

795 471 51 25

796 474 69 63

C. subcristatus and C.

pallidus G 807 T T A C T C T 492 T A T C T G C 75 A G A C G G T C 85 T C. marthae sp. nov. C 814 C A T T G T C 498 A G C T A A A 117 G A C T A A C T 92 C

831 525 135 93

847 528 147 167

Cytochrome b

867 536 171 168

868 547 207 179

873 550 249 198 C. subcristatus C 889 C C C C C C C 553 C C A T T T C 255 A A A G C C T 204 C G C. pallidus . 890 ....... 561 ....... 267 ....... 205 .. C. marthae sp. nov. T 891 T T T T T T T 573 A T C C C C T 291 G T T A T T C 247 T A

914 600 295 318

948 633 315 335

967 666 321 338

1014 683 363 508 C. subcristatus C Y R T C C C T G A C C T C T C T A A G T T G A

1053 693 369 509 C. pallidus . T G.....................

1059 700 372 512 C. marthae sp. nov. T G C C T T T C A G A T C T C A C G G C C C A C

1062 702 408 651

1068 706 411 696

1071 721 417 834

1081 723 426 850

1087 747 463 1098 C. subcristatus A T T C C C T C C T C T C C T G C G C A T A G C C. pallidus .... A................... C. marthae sp. nov. G C C T T T C T T C T C T G C A T A T G C G T A Meristic characteristics: N. supralabial scales: 7 (left side) and 9 (right side); n. infralabial scales: 10 (left side) and 9 (right side); n. scales around the parietal scale: 8; n. scales around the mental scale: 9; n. scales around the rostral scale: 8; n. scales along the middle-dorsal line: 17; n. scales around the inguinal scar: 46. Number of femoral pores: 19 (left leg) and 18 (right leg).

Morphological characteristics: Snout elongated, not shortened. Tympanum taller than wide. Scales flat or almost flat above the tympanum, in the post-orbital region. Slightly more elevated pyramid-shaped scales occur in the dorsal head.

Nuchal crest pronounced, adipose, with small conic scales which are reduced or almost flat along the ridge of the anterior half of the crest. Conic scales are more prominent, but not spinose, along the ridge of the posterior half. Dorsal crest less developed, with small conic scales along the ridge. Caudal crest poorly developed. Round-cross-section tail, not laterally compressed. Fingers of fore and hind legs with short claws, not recurved.

Coloration: pinkish head, pinkish and black (dark) body and legs, with a black-striped pattern on the mid to posterior dorsal body. On both sides, five vertical black stripes occur between forelimb and hind limb, along the dorsal-ventral axis. The first stripe is interrupted. Stripes 2–5 are joined horizontally, describing a complex pattern. Stripes are present but less evident on the ventral body. Dark tail.

Behavioral characteristics: The head-bob display (nodding behavior) consists of repeated modules. Each module comprises three series of multiple head movements (“ups and downs”; Fig. 6 a–c) and is completely executed within a time interval of 4–5 seconds. Frequency of movements performed in each series is high, with 4 to 6 movements per second. Two sub-series, separated by a few deciseconds, may be recognized within series 2. A fourth, additional series, similar to series 3, may be observed occasionally ( Fig. 6 d).

Etymology. The new species is named in memory of Martha Rebecca Gentile, second daughter of the first author. Martha prematurely left this world. She was born dead, as consequence of a medical doctor’s negligence, on August 20th 2003.

Distribution. Thus far, this species is known to occur only on Volcan Wolf ( Fig. 1 ), the northernmost volcano of Isla Isabela (Galápagos National Park, Ecuador).

Remarks. The new species is easily distinguished from the other two congeneric species. The color pattern is typical of the new species and was never observed in any of the populations of the other two named species. The origin and the nature of the pink pigmentation deserve further investigation. Nevertheless, it is instructive to note that when we surgically removed one pink scale, blood flowed out of the tissue of the removed scale, which immediately lost its pink color.

Traits i) and ii) in the diagnosis are more evident in males, whereas they are variable and generally less pronounced in females. Although in the Plaza Sur population of C. subcristatus almost flat dorsal head scales may be observed, such a trait never co-occurs in combination with the other traits characteristic of C. marthae sp. nov.

Although the “head-bob” pattern is slightly different between C. subcristatus populations in different islands (Gentile, unpublished data), the nodding behavior of C. marthae sp. nov. is very distinctive and characteristic. This is particularly relevant since it is exhibited in sympatry (syntopy) with C. subcristatus . None of the other species of land iguanas or any marine iguanas show a similar pattern (see Carpenter, 1982, for a comparison).

Conolophus marthae sp. nov. is distinct from the other two congeners by about 7% mtDNA genetic divergence, much higher than genetic divergence between C. pallidus and C. subcristatus (less than 2%, Gentile et al. 2009). Twenty-four nucleotide sites of the control region and seventy-two nucleotide sites in cyt b gene sequences are diagnostically different and allow distinguishing between the new species and the other congeneric ones. The deep divergence is estimated to have started in a period when the Galápagos did not have their current configuration ( Gentile et al. 2009). The absence of alleles shared with the other two species at the microsatellite locus CS7 and the presence of several private alleles at other loci ( Tzika et al., 2008; Gentile et al., 2009) indicate genetic isolation, even with the syntopic population of C. subcristatus .

Occasional hybridization between marine ( Amblyrhynchus cristatus Bell, 1825 ) and land iguanas ( C. subcristatus ) may still occur on Isla Plaza Sur, generating a black, brow-striped F1 hybrid ( Rassmann et al.,1997). Conolophus marthae sp. nov. lacks in any of the adaptive traits exhibited by marine iguanas (shortened snout; laterally compressed tail; developed caudal crest; long, recurved claws) and genetic data ( Gentile et al. 2009) provide strong evidence that C. marthae sp. nov. did not originate by hybridization between marine and land (yellow) iguanas. A total of 120 individuals of Conolophus marthae sp. nov. were observed and sampled in three field trips, in 2005, 2006, and 2009 (see the paragraph “Notes added in proofs”).

Besides the taxonomic implications, C. marthae sp. nov. is very important as it is the only evidence of deep divergence within the Galápagos land iguana lineage. In fact, the new species carries an ancient evolutionary legacy, being the only remnant of a lineage originated when the Galápagos archipelago did not have its present configuration. Conolophus marthae sp. nov. is a narrow endemism and its population size is small. Its inclusion in the Red List of the International Union for Conservation of Nature (IUCN) as "critically endangered" has been recommended ( Gentile et al. 2009).

Figures

FIGURE 1. Galápagos archipelago. Grey indicates islands were land iguana species occur or have occurred in historic times. Crosses indicate extinction in whole island. A dot indicates Volcan Wolf.

FIGURE 2. Conolophus marthae sp. nov. Holotype. Adult male with brand number 117 and PIT number 091 - 601 - 303. The individual is changing skin.

FIGURE 3. Conolophus marthae sp. nov. Holotype. Adult male with brand number 117 and PIT number 091 - 601 - 303. A – D) views of the head: right, frontal, left, and from above, respectively; E) dorsal view; F) ventral view. The individual is changing skin.

FIGURE 4. Conolophus marthae sp. nov. Adult male with brand number 118 and PIT number 091 - 062 - 369, held by A. Jaramillo, field assistant of the Charles Darwin Research Station. This individual is not the Holotype.

FIGURE 5. Conolophus marthae sp. nov. Adult male with brand number 36 and PIT number 091 - 336 - 546. Details of the head. This individual is not the Holotype.

FIGURE 6. Head-bob display of Conolophus marthae sp. nov. Multiple series (a, b, c, and d) of head-bob performed by the Holotype (June 2006). The series were performed with the following time intervals between each other: a – b, 27 seconds; b – c, 34 seconds; c – d, 11 seconds.