Geology topics

Cayla Lynn Carlson

Publications and source records attributed to Cayla Lynn Carlson.

2 recordsLinked to original sources

USGS2026

Black Carp Mylopharyngodon piceus reproductive development and maturation in the Mississippi River basin

Black Carp Mylopharyngodon piceus are native to most major east Asian drainages and are internationally cultured for use as a food-fish or a biological control for molluscs. We describe the reproductive biology of Black Carp from the growing invasive population in the Mississippi River basin through examination of incidental commercial fisheries and biologist captures. Our objectives were to assess (1) reproductive development by combined macroscopic and histological staging to compare reproductive maturation by total length, estimated age, and latitude; (2) population functions of gonadosomatic index, length and age, and weight and length relationships; and (3) absolute fecundity. We identified length as a better predictor of reproductive maturation than age, with variation among individuals, and between males and females, with higher probability of maturation anticipated for larger and older individuals predicted around 1050 mm total length (TL; 6 years) for females and 950 mm TL (5 years) for males ( n = 548). Proposed sizes and ages are representative minimum and should be interpreted with the understanding that spawning and recruitment success increase for older, more mature fish than in early stages. Observed growth rates were rapid relative to both native and introduced ranges. We confirmed that Black Carp are developmentally indeterminate batch spawners due to the simultaneous presence of advanced growth oocytes via histology and egg measurements, with preserved egg average diameters ranging from 0.395 to 3.215 mm ( n = 23). Absolute fecundity estimates ranged from 72,748 to 3,542,789 eggs across the 966 to 1412 mm TL size range of individuals, with substantial variability among individuals attributed to poor relative fecundity estimates. These results represent the first step in assessing the reproductive rates of Mississippi River Black Carp via the size of reproductive development and potential contributions through fecundity. The results and population rates presented here may be used or adapted for future studies on regional spawning phenology and reproductive development, or in population growth models for control.

Arkansas, Illinois, Indiana, Kentucky, Louisiana, ↗

USGS2026

Validation of daily age in Grass Carp reared in tanks and outdoor ponds in the U.S. Midwest

Objective Accurate and precise age estimation is essential for understanding early life history, recruitment, and population dynamics in fish. However, daily otolith increment deposition has not been validated for Grass Carp Ctenopharyngodon idella in the Midwestern United States. Our objective was to validate daily increment deposition in lapilli otoliths of known-age Grass Carp that were reared under controlled laboratory and outdoor pond environments and to evaluate the reliability of otolith-based daily age estimation across early life stages. Methods Larval Grass Carp that were hatched from captive broodstock were reared in indoor tanks and outdoor ponds and sampled between 6 and 120 d posthatch. The lapilli otoliths were extracted, lightly sanded, and independently read three times to estimate age. The estimated ages were compared with known chronological age to assess the accuracy and precision of daily increment counts across rearing environments. Results Daily increment deposition was validated through 51 d posthatch for the tank-reared fish and through 69 d posthatch for the pond-reared fish. Beyond these ages, the estimated ages increasingly underestimated known age due to compression of daily increments near the otolith core and outer margin, particularly in slower growing individuals. Growth rates differed substantially between the two rearing environments and influenced increment spacing and readability. Otolith size was strongly correlated with the total length of the fish but decreased relative to chronological age as increment compression increased, particularly in fish exceeding approximately 40–50 mm total length (TL) in tank-reared and 60–70 mm TL in pond-reared individuals. Conclusions Lapilli otoliths provide reliable daily age estimates for Grass Carp during early life stages under both laboratory and pond conditions. These validated methods enable robust estimation of hatch timing and early growth, providing a foundational tool for studying early life history and informing control efforts for invasive Grass Carp populations

Missouri↗