. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. 62 ANNALS OF THE SOUTH AFRICAN MUSEUM. Fig. 6. Helicolenus dactylopterus a. Larva at lo mm standard length showing external features only. b. Dorsal view of head showing position of spines, c. Lateral view of head showing position of cranial bones and spines: I. Dentary. 2. Angular. 3, Articular. 4. Quadrate. 5. Branchiostegal rays. 6. Preopercle and five spines. 7. Subopercle. 8. Opercle. 9. Postcleithrum. 10. Posttemporal and spines. 11. Hyo- mandibular. 12. Pterotic and spine. 13. Parietal and spi
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. 62 ANNALS OF THE SOUTH AFRICAN MUSEUM. Fig. 6. Helicolenus dactylopterus a. Larva at lo mm standard length showing external features only. b. Dorsal view of head showing position of spines, c. Lateral view of head showing position of cranial bones and spines: I. Dentary. 2. Angular. 3, Articular. 4. Quadrate. 5. Branchiostegal rays. 6. Preopercle and five spines. 7. Subopercle. 8. Opercle. 9. Postcleithrum. 10. Posttemporal and spines. 11. Hyo- mandibular. 12. Pterotic and spine. 13. Parietal and spines, 14. Frontal and supraorbital spine. 15. Premaxilla. 16. Maxilla. 17. Nasal and spine. 18. Lacrymal and suborbital spine. 19. Cir- cumorbitals. 20, Prefrontal. 21. Pterygoid. 22. Cleithrum. Gillrakers and gill-arches have started ossifying. A ceratohyal, quadrate and traces of the pterygoid are visible. By 6,6 mm the lacrymal and endopterygoid are formed and the lacrymal bears a spine. Frontal and parietal are fused. Supratemporal and spine are evident. Six branchiostegal rays are ossified. By 7,35 mm the lacrymal is larger and bears two spines while the first and second suborbital are well ossified, obscuring the pterygoid to some extent. Thirteen gillrakers are present and the sutures between parietal, pterotic, posttemporal and hyomandibular have become indistinct. In the size range 6,6 to 7,35 mm the head spines present are: supraocular, parietal, pterotic, supratemporal, preorbital, suborbital, three primary and two secondary preopercular. Between 7,35 and 9,0 mm ossification of the head proceeds to near juvenile condition. New elements added include nasal spines, two extra primary preopercular spines and traces of a preocular. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original South African Museum. Ca
Size: 1588px × 1573px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
