Document Type

Internship Report

Publication Date

Fall 2017

Abstract

The Guadalupe Bass Micropterus treculii (GB) is a freshwater, black bass endemic to Texas. Currently, GB fry are reared using methods developed for Largemouth Bass Micropterus salmoides (LMB) due to the lack of species-specific information. The results have been variable (11-70% fingerling survival in ponds). This paper aims to fill in gaps in the GB early life history in order to improve rearing practices. The first experiment measured eggs from 47 different spawns to find an average GB egg diameter (2,008.16±98.98 µm, range: 1,622.44-2,312.65 µm, which is larger than LMB eggs). The second experiment used fry from 30 different spawns to find an average TL of a newly stocked GB (8.26±0.2 mm) and the average dorsal gape width (750.10±79.28 µm), which allows them to consume Artemia nauplii upon first feeding. Fry were also sampled from the stocking ponds and their guts examined to observed feed preferences. The most commonly found prey items inside newly stocked fry were rotifers, rotifer eggs, and chironomids, along with occasional copepods, and cladocerans. At two weeks old, fry began consuming corixidae and ephemeroptera. The third experiment consisted of eggs and fry held at 20°C and 24°C water baths. At the higher temperature, the GB had a shorter incubation period, and faster development and yolk depletion. The typical hatching time for eggs at 21°C was 61.1 ±4.4 hours, while the eggs kept at 24° hatched at around 47.9±2.9 hours. At 24° the yolk was present up to 9-11 days post hatch (dph) and the oil globule up to 14 dph.

Comments

Department: MES

MPS Track: AQU

Location: A. E. Wood State Fish Hatchery

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