Congenital Anomalies in American Crocodile (Crocodylus acutus, Cuvier, 1807) Embryos from a Farm Breeder in Colombia

Abstract

The American crocodile (Crocodylus acutus, Cuvier, 1807) (Class Reptilia, Family Crocodylidae) is a crocodile species inhabiting the Neotropics. Congenital defects have been described in almost every vertebrate group. In crocodiles, teratology alterations have been described in captive animals (pets, zoos, farms) such as Crocodylus niloticus or Gavialis gangeticus. The present study aimed to characterize congenital malformations of C. acutus from a farm in Lomas de Matunilla, Ballestas, Bolívar, Colombia. A total of 550 unhatched eggs were examined after embryo death. A total of 61 embryos presented malformations, with 42 different types of anomalies observed. Limb and tail malformations (29%) were the most common malformations observed. Several malformations, such as cephalothoracopagus, thoracopagus, sternopagus, xiphopagus twins, campylorrachis scoliosa, and acrania, were documented in crocodiles for the first time. Research in teratology enhances our understanding of crocodile biology. It plays a role in their conservation and management, thus helping to ensure the long-term viability of these species in their natural habitats.

Keywords: Crocodylus acutus; caimán aguja; embryos; malformations; teratology.

Figure 1

Colombia map with the location of the American crocodile (Crocodylus acutus Cuvier, 1807) farm.

Figure 2

Malformation distribution by anatomical region in 61 embryos of the American crocodile (Crocodylus acutus Cuvier, 1807).

Figure 3

Ephitheliogenesis imperfecta in the lower jaw (↑) (A), eyes (↑) (B), absence of scales on the entire body (C) in Crocodylus acutus embryos. Scale bar = 5 cm.

Figure 4

Leucism (A,B), depigmentation (↑) (C) Crocodylus acutus embryos. Scale bar = 2 cm and 5 cm.

Figure 5

Lordosis, kinked tail (↑), and yolk sac retention with non-closure of the abdominal wall in a Crocodylus acutus embryo ((A,B)—Lateral view, (C)—dorsoventral view). Scale bar = 5 cm.

Figure 6

Yolk sac retention with non-closure of the abdominal wall, kinked tail, scoliosis and kyphosis in a Crocodylus acutus embryo. ((A)—Lateral view, (B)—ventral view, (C)—dorsoventral view). Scale bar = 5 cm.

Figure 7

Yolk sac retention with non-closure of the abdominal wall, maxillary macrognathia (↑ yellow), acrania (↑ white), curved tail, and campylorrachis scoliosa in Crocodylus acutus embryo. (A,B)—Lateral view, (C)—cranial view). Scale bar = 3 cm and 1 cm.

Figure 8

Maxilla agnathia (↑ white), microphthalmia (↑ yellow), acaudia, and leucism in Crocodylus acutus embryo. ((A,B)—Lateral view, (C)—cranial view). Scale bar = 2 cm and 1 cm.

Figure 9

(A) Maxillary micrognathia and atresia; (B) maxillary micrognathia; (C) maxillary macrognathia and laterognathia; (D) Laterognathia in Crocodylus acutus embryos. Scale bar = 2 cm and 3 cm.

Figure 10

Depigmentation of the skin, mandibular micrognathia (↑ red), microcephaly, gastroschisis, ectopia cordis (↑ white), schistosomia, kyphosis, meningoencephalocele (↑ yellow), bend tail, epitheliogenesis imperfecta in all the body in Crocodylus acutus embryo ((A,C)—Lateral view, (B)—Head). Scale bar = 2 cm and 1 cm.

Figure 11

Leucism, acephalostomia, anophthalmia, atresia, and curly tail in Crocodylus acutus embryo. ((A)—Lateral head view, (B)—Lateral body view, (C)—cranial view). Scale bar = 2 cm and 5 cm.

Figure 12

Yolk sac retention, meningoencephalocele (↑ white), kinked tail, exophthalmia, and brachygnathia in Crocodylus acutus embryo. ((A)—Lateral body view, (B)—Cranial view, (C)—Lateral head view, (D)—dorsoventral view). Scale bar = 5 cm.

Figure 13

Kinked tail, maxillary micrognathia (↑ white), exophthalmos in both eyes, brachycephalic skull, ankylodactyly of the two digits fused in the left posterior member (↑ yellow), congenital cataract in both eyes, tubercles on top of the skull (↑ red), and epitheliogenesis imperfecta on the palpebra Crocodylus acutus embryo. ((A)—Lateral body view, (B)—Cranial view, (C)—ventrodoral head view, (D)—lateral head view, (E)—ventrodorsal view). Scale bar = 5 cm and 2 cm.

Figure 14

Polydactyly in the posterior right limb with two extra fingers, distended celomic cavity, tail blunt-tipped, bent tail, and brachyury in Crocodylus acutus embryo. ((A)—Limb view, (B)—ventrodorsal view). Scale bar = 1 cm and 5 cm.

Figure 15

(A) Kinked tail; (B) acaudia; (C) curved tail Crocodylus acutus embryos. Scale bar = 5 cm.

Figure 16

Achondroplasia, scoliosis, yolk sac retention, micromelia of the left upper member, and curly tail Crocodylus acutus embryo. ((A)—Ventrodorsally view, (B)—Lateral view, (C)—Dorsal ventral view). Scale bar = 5 cm.

Figure 17

Cephalothoracopagus twins, curly tail, epitheliogenesis imperfecta at the top of the skull, and yolk sac retention in Crocodylus acutus embryo. ((A,B)—Lateral view, (C)—Ventrodorsal view). Scale bar = 5 cm.

Figure 18

Monozygotic Symmetrical Twins of Crocodylus acutus. ((A)—Ventra dorsal view, (B)—Lateral view, (C)—Dorsal ventral view). Scale bar = 5 cm.