Larval development of the hooked mussel, Brachidontes recurvus Rafinesque (Bivalvia: Mytilidae) including a literature review of the larval characteristcs of the Mytilidae

Brachidontes recurvus larvae were reared from eggs in the laboratory. Larval length increased from 90-220 μ, during shelled stages with straight-hinge stage from 90-165 μ,, umbo stage from 135-220 μ,, and pediveliger stage from 165-220 μ,. Height was 23 ± 10 μ. less than length. Depth was 54 + 15 μ, less than length. The hinge line increased with growth and ranged from 68-84 μ,- Hinge structure consisted of small taxodont hinge teeth over the entire hinge line with teeth becoming larger at both ends. Larvae are typical D-shaped mytilid larvae during straight hinge stages but develop a conspicuous, broadly rounded umbo and steeply sloping shoulders. Ends are blunt and the ventral margin flattened. The eyespot appears at a length of about 165 μ. Larvae are more likely to be confused with larvae of Modiolus demissus than those of other bivalves

Larval development of the coquina clam, Donax variabilis Say, with a discussion of the structure of the larval hinge on the Tellinacea

Adult specimens of Donax variabilis were spawned in the laboratory and the larvae reared to metamorphosis. Larval length increases from 70 p. to 340 p. during pelagic stages. Height is originally 10 p. to 15 μ. less than length. Height increases less rapidly than length and may be 50 μ. less than length at metamorphosis. Depth is originally 50 μ. less than length. It also increases more slowly than length and may be 150 p. to 170 μ. less than length at metamorphosis. Length of the hinge line is 50 μ. to 60 p.. Round umbos form when larvae are 100 p. to 120 μ. long. Umbos protrude above the shell as knobby projections at lengths above 170 μ.. The anterior and posterior ends are equally rounded until, at about 250 p., the posterior end becomes more pointed. Larvae metamorphose at lengths from 275 μ. to 340 p.. The hinges of the larvae of D. variabilis and Tellina agilis consist of numerous small irregular teeth. Descriptions of taxodont dentition in larvae of other Tellinacea are probably in error and refer to these small irregular teeth. The large special teeth, frequently described in larvae of this group, probably do not develop until after metamorphosis

Larval development of the large blood clam, Noetia ponderosa (Say)

Larvae of Noelia ponderosa were raised from eggs in laboratory cultures. Lengths increased frorn 80 to 210μ, over a 4-week free- swimmining period. Height is 15 μ, less than length in small larvae but as much as 55 μ, less than length when larvae are ready to metamorphose. Depth varies front 25 to 70 μ. less than length over the same period. The straight-hinge line is 65 to 80 μ, long. The umbo is first for1ned at a length of . 150 to 160 μ. and beco1nes long and broad. Umboned larvae are brown with the shell becoming reddish-brown at the anterior end. However, these typically arcid colors are not as dark as in other species of this family. \u27l\u27he anterior end is more pointed than the posterior in umbo larvae. The hinge consists of a central undifferentiated area with a series of small taxodont teeth at both the anterior and the posterior end of the hinge line in both valves

EVALUATION OF A POST-BACCALAUREATE MEDICAL EDUCATION PROGRAM FOR DISADVANTAGED STUDENTS TO DIVERSIFY THE HEALTHCARE WORKFORCE IN HAWAIʻI (1996 – 2016)

Ph.D

Larval development of the pelecypod Lyonsia hyalina

L)1011sia hyalina (Conrad) is a small ( 1/2 to 3/4 inch) odd shaped clarn (Fig·. I) common along the Atlantic Coast from Nova Scotia to South Carolina (Abbott, 1954). It is usually found in sand in shallow water with a coating of small sand grains attached to the periostracurn. (...

Endometriosis Among Women Exposed to Polybrominated Biphenyls

We examined the association between endometriosis and exposure to polybrominated biphenyls (PBBs) and polychlorinated biphenyls (PCBs) among women inadvertently exposed to PBBs in 1973