Mexican lamprey

📖 Overview

Freshwater . Found in streams, rivers, and lakes over substrates of firm mud, silt, and rock . Spawning habitat is a fast-flowing, clear-water stream with a stony substrate. Eggs hatch between the months of November and January and ammocoetes undergo metamorphosis at the end of three years . Ammocoete larval stage duration also cited as four years . Ammocoetes live in the mud and feed on plankton (algae of the genera Rhizosolenia, Pleurosigma, Pinularia, Stauroneis, Amphora, and Cocconema, filamentous Chlorophyceae, rotifers, ciliates, and occasionally euglenoid flagellates). The mean total length reached at the end of the first year of larval life is 83 mm; at the end of two years, 135 mm; and at the end of three years, 146 mm. During the rainy season (July) of their first year, ammocoetes exhibit a shrinkage in their total length. Metamorphosis occurs in April-August . Parasitic . Following metamorphosis, adults migrate to Lake Chapala or the Duero River (Lerma River Basin) where they live as ectoparasites of fishes (carp and catfish) for two years. The diet appears to be predominantly blood. A large number of scales of Moxostoma austrinum and either of Algansea popoche, Yuriria alta, or Y. chapalae, as well as possibly Chirostoma sp. has been found mixed with blood in the intestine of adults. Attacks on the small cyprinids and the atherinopsid almost certainly resulted in their death. Around late June, early July they begin to migrate upstream to the spawning grounds in the upper reaches of the Celio River and die after spawning. Nine individuals in spawning readiness were collected on 19 November (water temperature was about 20°C). Fecundity, 6,617-9,095 eggs/female. Egg diameter, 0.7-0.8 mm. Is presumed to kill a certain number of commercial fish species (Algansea popoche and Chirostoma sp.) in Lake Chapala .

🔬 Taxonomy

🐟 Physical Description

Adults: 18-31 cm TL. Body wet weight of individuals measuring 18.7-22.5 cm TL, 21.3-26.3 g. Body proportions, as percentage of TL [based on 54 specimens, TL range inferred to be roughly 18-31 cm TL, Álvarez del Villar (1966)]: prebranchial length, 10.9-15.7; branchial length, 8.2-13.6; trunk length, 41.0-50.3; tail length, 27.2-34.3. Trunk myomeres, 60-65. Dentition: supraoral lamina, 2 unicuspid teeth, but 20% of individuals had 1-2 additional unicuspid teeth on the bridge; infraoral lamina, 5-9 unicuspid teeth, of which 4-5 are large and 0-4 are small (84% of specimens possess both large and small cusps); 4 endolaterals on each side, exceptionally 3 or 5; endolateral formula, typically 2-2-2-2, rarely, one of the teeth is tricuspid; 3 rows of anterials; first row of anterials, 6 unicuspid teeth; 1 row of exolaterals; 1 rows of posterials; first row of posterials, 21 unicuspid teeth; transverse lingual lamina weakly u-shaped, 17-22 unicuspid teeth, the median one or two unicuspid teeth slightly enlarged; longitudinal lingual laminae parentheses-shaped, each with 24-25 unicuspid teeth. Velar tentacles, 19-21, with tubercles; the dorsal wings are long, reaching the median tentacle. Lateral line neuromasts unpigmented. Caudal fin pigmentation, 75% or more. Caudal fin shape, spade-like. Oral fimbriae, 109-136. Oral papillae, 13-27.: eel-like.

🌀 Behaviour

Behavioural data for Mexican lamprey is currently being reviewed.

🦐 Diet

🥚 Reproduction

🌍 Habitat & Distribution

Freshwater; demersal; potamodromous . Tropical; 21°N - 19°N North America: Celio, Duero and Lerma rivers and Lake Chapala, Mexico.

🌿 Ecology

📐 Morphometrics

🌡️ Water Parameters & Tolerance

🛡️ Conservation Assessment

📊 Population Risk & Fisheries

🐠 Related Species

👥 Community & Contribute