36 years after the species\u27 mass-mortality: Diadema antillarum test sizes, population densities, and substrate preferences in three Guna Yala reefs near Wichub Wala Island

In January 1983, a waterborne pathogen beginning near the Atlantic Panama Canal entrance caused history\u27s largest recorded marine animal die-off, wiping out 95-99% of Diadema antillarum populations throughout the Caribbean. D. antillarum, the long-spined sea urchin, is a keystone herbivore in coral reefs and its decreased densities have caused many reefs to suffer macroalgal phase shifts. Modest recovery of this species has been documented in some Caribbean locations, but reefs in Guna Yala, Panama continued to experience population decline. This study investigates density, test size, and substrate preferences of D. antillarum in three shallow coral reef areas to update the species\u27 recovery in Guna Yala. Over the total 1,080 m2 of reef surveyed, D. antillarum was present at a mean density of 0.11 individuals m-2. This is only 3.03% of the 1982 pre-mortality density for the area, but is a slight recovery from the 2015 density of 0.03 individuals m-2. This study was the first to document test sizes in Guna Yala in 24 years and did so at novel reef sites. Test sizes ranged from 8-62.5 mm with a mean of 38.85 mm, and the presence of 6 juveniles (test size\u3c2 cm) indicates a level of recruitment. Out of the total 119 urchins counted, 94 individuals were located under dead coral skeletons covered in algae. There were no significant relationships (p\u3c0.05) between urchin test sizes and the type of substrate they resided on (within live coral, under live coral, under dead coral, or under rocks), suggesting that a factor other than size determines where D. antillarum are located within a reef, and that D. antillarum in Guna Yala could potentially aid in phase shift reduction due to their exhibited preference for algae-covered surfaces. This study demonstrated consistent average densities, test sizes, and substrate preferences between the three sites, indicating that the different sites are experiencing similar population recovery phenomena despite their varying observed characterizations. The consistent results between sites bode well for this study\u27s representation of D. antillarum\u27s current status in Guna Yala reefs

Post-larval growth in the blue marlin

20 p. : ill. ; 24 cm.Includes bibliographical references (p. 19-20)

On Caranx crysos (Mitchill)

4 p. : ill. ; 24 cm

The osteology and relationships of the wahoo (Acanthocybium solandri), a scombroid fish. American Museum novitates ; no. 1000

32 p. : ill. ; 24 cm.Includes bibliographical references (p. 31-32)."A study of the osteology of the highly specialized scombroid, Acanthocybium solandri, substantiates the work of previous authors in placing it in the family Scombridae. Prolonged consideration of its alleged relationship to the xiphiiform fishes brings out the following points: 1. Acanthocybium is unique among the Scombridae in its extremely long and shallow body which reflects externally its many segmented vertebral column. The Xiphiiformes, on the other hand, have a pseudo-dolichosomy which is brought about by the long sword alone, for they have the fewest number of vertebrae of any species in the order (with the exception of Luvarus imperalus). 2. In quality of body form Acanthocybium is one of the Scombridae and is quite unlike the Xiphiiformes. 3. Comparison of the skulls of Acanthocybium, Istiophorus, and Xiphias shows that the specializations seen in the Xiphiiformes are the result of altered stress developing with the evolution of the sword. 4. However, the sword may just as easily have arisen from the primitive Scomber as from Acanthocybium, for both have equally pronounced premaxillae. 5. A common scombroid heritage is indicated by the general similarity of neurocrania in the three genera studied. 6. The quality of the vertebral column as a whole is very different in all three genera ... 7. The individual vertebrae of the three types are so very different in form that it is evident that one is dealing with three divergent lines of scombroid evolution. It is concluded, therefore, that the wahoo, Acanthocybium solandri, is an aberrant but true member of the Scombridae with no genetic relation or even parallelism to the Xiphiiformes. If descendants of an Acanthocybium-like ancestor are to be sought perhaps they may he found among the primitive cutlass-fishes, such as Ruvettus, which are characterized by many segmented columns"--P. 30

Observations on body form of the blue marlin

p. 207-220 : ill. ; 25 cm.Includes bibliographical references (p. 220)