Shovelbill shark (Sphyrna alleni), hammerhead shark (Sphyrnidae) from Caribbean and Southwest Atlantic

NEWS - Researchers have identified a new species of hammerhead shark as the shovelbill shark or Requin-marteau pelle or Tiburón Cabeza de Pala (Sphyrna alleni) collected at Robinson Point and Riversdale Village, Belize, and provided by local fishermen in 2016 and 2019. S. alleni is named after Paul G. Allen (1953-2018), a philanthropist who supported shark research and conservation.

Shovelbill shark is max 150 cm long when mature with a flat, shovel-shaped head that lacks a notch on the anterior margin, a pointed (triangular) cephalofoil in both sexes and a distinct protrusion in males. The posterior margin is lobulated.

The posterior teeth are enlarged, molar-like, the first dorsal tip is anterior to the pelvic origin and the posterior margin of the anus is shallowly concave. It differs from S. tiburo in that the anterior margin of the head is more rounded and the posterior margin lacks lobules. The number of precaudal vertebrae for S. alleni is between 80-83 (~10 more vertebrae than S. tiburo).

The distribution range is in coastal waters, estuaries, coral reefs, seagrass beds and sandy bottoms from Belize to Brazil. Its presence has been confirmed in the Caribbean in Belize, Panama, Colombia, Trinidad and Tobago and in the southwest Atlantic in Brazil.

S. alleni and S. tiburo are separated into two gene pools when examining 12 nuclear microsatellites with many private alleles observed. Visual inspection reveals a more pointed anterior margin of the cephalofoil in S. alleni which is consistent with geometric morphometric analysis and precaudal vertebrae count.

These species diverged between 3.61-5.62 million years ago which would be before the uplift of the Isthmus of Panama. It is possible that S. alleni and S. vespertina are sister lineages and S. tiburo diverged from them as it expanded into the subtropical and temperate regions of the Atlantic.

Phylogenetic reconstruction and head morphology also suggest S. tiburo is a species complex consisting of south central (Caribbean), northwestern (Gulf of Mexico, Florida, South and North Carolina) and eastern Pacific lineages.

Bonnetheads are currently rated as Globally ‘Endangered’ by the IUCN, but they have been assessed as an American amphibian species. The species is well managed in the higher latitudes of its Northern Hemisphere Atlantic range, but is heavily fished and poorly managed elsewhere.

Original research

Cindy Gonzalez, Bautisse Postaire, William Driggers, Susana Caballero & Demian Chapman (2024), Sphyrna alleni sp. nov., a new hammerhead shark (Carcharhiniformes, Sphyrnidae) from the Caribbean and the Southwest Atlantic. Zootaxa 5512 (4): 491–511, DOI: 10.11646/zootaxa.5512.4.2

Dlium theDlium

Thomas Sutikna lives with Homo floresiensis

BLOG - On October 28, 2004, a paper was published in Nature describing the dwarf hominin we know today as Homo floresiensis that has shocked the world. The report changed the geographical landscape of early humans that previously stated that the Pleistocene Asia was only represented by two species, Homo erectus and Homo sapiens . The report titled "A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia" written by Peter Brown and Mike J. Morwood from the University of New England with Thomas Sutikna, Raden Pandji Soejono, Jatmiko, E. Wahyu Saptomo and Rokus Awe Due from the National Archaeology Research Institute (ARKENAS), Indonesia, presents more diversity in the genus Homo. “Immediately, my fever vanished. I couldn’t sleep well that night. I couldn’t wait for sunrise. In the early morning we went to the site, and when we arrived in the cave, I didn’t say a thing because both my mind and heart couldn’t handle this incredible moment. I just went down...

Bitter vine (Mikania micrantha)

Sembung rambat or bitter vine ( Mikania micrantha ) is a plant species in Asteraceae, crawling or wrapped around trees, perennial that grows up to 27 mm per day in tropical climates, branched stems where heart-shaped or triangular leaves are arranged in pairs and a plant can cover more than 25 square meters in a few months. M. micrantha has square-shaped stems or longitudinal bones, light green, many branches and has fine hairs. The stems have segments for lengths of 75-215 mm, each segment has a pair of leaves, new shoots and flowers. New roots grow when the segments come in contact with the soil. The leaves are in pairs and facing each other. Strands do not have hair, heart-shaped or triangular with jagged edges, length 30-125 mm, width 15-60 mm. Petiole is 1-6 cm long and has fine hairs. The flower panicle grows from the armpit of the leaf and the tip of the stem, having 3-15 mm long stems. Each flower head has 4 minor flowers. The crown is greenish-white, tubular and measures ...

Cogon grass (Imperata cylindrica)

Alang-alang or cogon grass ( Imperata cylindrica ) is a plant species in Poaceae, annual grass, sharp leaf, long buds and scaly, creeping under the ground, very adaptive and grows in all climates which often become weeds on agricultural land. I. cylindrica has a sharp pointed tip of the bud and emerges from the ground, height of 0.2-1.5 m but in other places it may be more, short stems, rising up to the ground and flowering white or purplish, often with wreath of hair under the segment. Leaf strands in the form of long ribbons, lancet-tipped with a narrow base and gutter-shaped, 12-80 cm long, very coarse edge and jagged sharply, long hair at the base with broad, pale leaf bones in the middle. The flowers are panicles, 6-28 cm long with long-haired and white-colored ears for 1 cm which are used as a tool to blow off the fruit when ripe. Cogon grass breeds quickly with seeds that spread quickly with the wind or through rhizomes that quickly penetrate the soil. Alang-alang does...

Dlium