Semen collection, characterization, and cryopreservation in a Magellanic penguin (Spheniscus magellanicus)

A cooperative method was developed for collecting semen from a Magellanic p enguin. Ejaculate parameters and semen production during a breeding season were characterized. Experiments were performed to study the effect on pengu in spermatozoa of two temperatures (4 degrees C and 21 degrees C) for short -term storage, and two cryoprotectants (dimethylsulfoxide [DMSO] and ethyle ne glycol [EG]) for long-term storage (cryopreservation). All dilutions wer e made using modified Beltsville Poultry Semen Extender. Sperm quality was assessed by evaluating motility and forward progression (sperm motility ind ex [SMI]), viability, and morphology. A total of 39 ejaculates was collecte d over the 40-day study period. Thirty-eight ejaculates contained spermatoz oa, but semen quality decreased toward the end of the study period. Varying levels of urate contamination were present in all ejaculates. Sperm qualit y parameters were similar for diluted samples held at 4 degrees C and 21 de grees C, and samples maintained high numbers of viable (77.8 +/- 5.4%) and morphologically normal (67.9 +/- 2.5%) spermatozoa at 3 hr. SMI and percent age of viable sperm decreased (P < 0.05) and the number of spermatozoa with a bent head or midpiece increased (P < 0.05) for both temperature groups o ver the 3-hr storage interval. DMSO and EG were equally effective in mainta ining penguin sperm quality parameters during the cryopreservation and thaw ing process. Frozen-thawed semen maintained 69 +/- 5 and 78 +/- 3% of its p re-freeze SMI and viability, respectively. SMI and viability decreased slig htly during the cooling and equilibration phases but remained relatively st able during the 3-hr storage interval post-thaw. Frozen-thawed semen also e xhibited an increase (P < 0.05) in spermatozoa with a bent head or midpiece over time. The pre-freeze SMI was higher (P < 0.05) for ejaculates with lo w levels of urates (clean ejaculates) compared with ejaculates with high le vels of urate contamination, but sperm viability and morphology were simila r (P > 0.05). Both SMI and viability of frozen-thawed spermatozoa were high er (P < 0.05) for clean than for contaminated ejaculates. This is the first report on penguin ejaculate parameters, semen production, and preliminary Methods for short- and long-term semen storage. (C) 1999 Wiley-Liss, Inc.