Evidence map›Paper›PMID 42504861›Full record

ArticleJournal of morphology2026

Ultrastructure and Function of the Male Reproductive System in the Rotifer Asplanchnopus cf. multiceps (Rotifera: Monogononta).

Thiago Quintão Araújo, Robert L Wallace, Elizabeth J Walsh, Rick Hochberg

Abstract read
In one paragraph

Article in Journal of morphology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Thiago Quintão AraújoDepartment of Biological Sciences, University of Massachusetts Lowell, Lowell, Massachusetts, USA.ORCID https://orcid.org/0000-0001-9325-6248
Robert L WallaceDepartment of Biology, Ripon College, Ripon, Wisconsin, USA.ORCID https://orcid.org/0000-0001-6305-4776
Elizabeth J WalshDepartment of Biological Sciences, University of Texas at El Paso, El Paso, Texas, USA.ORCID https://orcid.org/0000-0002-6719-6883
Rick HochbergDepartment of Biological Sciences, University of Massachusetts Lowell, Lowell, Massachusetts, USA.ORCID https://orcid.org/0000-0002-5567-5393

Funding

National Science Foundation DEB 2051684National Science Foundation DEB 2051704National Science Foundation DEB 2051710
6 · The paper itself

Abstract

Male rotifers are both rare and inconspicuous members of freshwater environments. Consequently, their anatomy is poorly known, and many details about sexual reproduction remain vague. Here, we explore the reproductive anatomy of the dwarf male of Asplanchnopus cf. multiceps using light microscopy, confocal microscopy, and transmission electron microscopy to describe its fine structure and function and compare it to what is known among other male rotifers. We reveal a male system consisting of a single testis and vas deferens, two prostate glands, and several muscles that function for copulation. The testis is comprised of a thin cellular lining that surrounds spindle-shaped spermatozoa and tapered rods with an ultrastructure similar to those in Asplanchna. Both are released from the testis via a junctional sphincter, which permits their entry into a ciliated vas deferens. The vas deferens consists of three hollow cells, the most distal of which is a copulatory cell that projects into a partly ciliated male canal. During copulation, retractor muscles dilate the canal opening before a semicircular muscle contract to increase hydrostatic pressure at the posterior end. We hypothesize this pressure forces secretions from the prostate glands out the opening and just prior to canal evagination. The hollow copulatory cell at the base of the vas deferens is centered in this evagination and together creates a bulbous copulatory organ that projects from the rotifer's posterior end. This copulatory cell has microvilli that may help to form a strong bond with the prostatic secretions on the female integument. Longitudinal muscles along the vas deferens contract and pressurize the vessel, thereby ejecting rods and spermatozoa through the female integument. Additional muscles function to retract the entire complex back into the body. The organization of the reproductive system is similar to males of Asplanchna and this study expands on what is known from historical light microscopical analyses.

Indexed as

Genitalia, MaleRotiferaAnimalsCopulationMaleMicroscopy, Electron, TransmissionReproductionSpermatozoaTestisVas Deferenscopulationpenisspermtestiszooplankton

Identifiers

PMID42504861
PMCPMC13403294

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.